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- A -
ab initio calculations アブイニシオ計算、第一原理計算
absolute configuration 絶対配置、絶対立体配置
absorbance 吸収度、吸光度
absorption coefficient 吸収係数
abstraction 抽出、抜き取ること
acceptor 受容体
accuracy 正確さ
acetal アセタール
（ケタールも現在はアセタールと呼んでいる）
acetaldehyde アセトアルデヒド CH3CHO
acetamide アセトアミド CH3CONH2
acetanilide アセトアニリド AcNHPh
acetic acid　 酢酸 CH3CO2H
acetic anhydride 無水酢酸 (CH3CO)2O
acetoacetic ester synthesis アセト酢酸エステル合成法
acetone アセトン
acetonide アセトニド
acetonitrile アセトニトリル CH3CN
acetophenone アセトフェノン PhCOCH3
acetyl chloride 塩化アセチル CH3COCl
acetylacetone アセチルアセトン
acetylene アセチレン HC≡CH
acetylide アセチリド
achiral アキラル
acid 酸
acid anhydride 酸無水物
acid-base catalysis 酸塩基触媒
acid-base titration 酸塩基滴定
acidity 酸度
acrolein アクロレイン
acrylamide アクリルアミド
activated charcoal 活性炭
activation energy 活性化エネルギー
acute toxicity 急性毒性
acyclic 　 非環式
acyl halides 酸ハライド
acylation アシル化
acylium ion アシリウムイオン R-C≡O+
acyloin condensation アシロイン縮合
adamantane アダマンタン
Adams catalyst アダムズ触媒 PtO2
additivity rule 加成性則
adduct 付加体
adenine アデニン
adenosine アデノシン
adipic acid　 アジピン酸
adsorbent 吸着剤
adsorption 吸着
adverse effect 有害反応、有害事象、有害効果
aerobic 好気性、空気のある
affinity chromatography 親和性クロマトグラフィ
aggregate 集合体
aglycon アグリコン
agonist アゴニスト、作動薬、作用薬、活性化薬
air pollution 空気汚染、大気汚染
alanine アラニン
albumin　 アルブミン
alcohol　 アルコール R-OH
alcoholysis 加アルコール分解
aldehyde アルデヒド
Alder-ene reaction アルダーエン反応
aldimine アルジミン
aldol reaction アルドール反応
aldose アルドース
aldoxime アルドキシム RCH=NOH
alicyclic compound 脂環式化合物
aliphatic 脂肪族の、脂肪質の
alkali metal アルカリ金属
alkaloid アルカロイド
alkane　 アルカン
alkene　 アルケン
alkoxide アルコキシド
alkoxy アルコキシ
alkyl halide ハロゲン化アルキル R-X
alkylating agent アルキル化剤
alkylation アルキル化
alkylidene carbene アルキリデンカルベン
alkyllithium reagent アルキルリチウム試薬 R-Li
alkyne　 アルキン
allene アレン
allosteric enzyme アロステリック酵素
allyl radical アリルラジカル
allylic strain アリルひずみ
α-ketoglutaric acid α-ケトグルタル酸　
aluminum アルミニウム Al
Amadori rearrangement アマドリ転位
ambident nucleophile アンビデント求核剤
amide アミド
amidine アミジン
aminal アミナール
amination アミノ化
amine アミン
amino acid アミノ酸
aminolysis 加アミン分解
ammonia アンモニア NH3
ammonium chloride 塩化アンモニウム NH4Cl
amylose アミロース
anaerobic 無気呼吸、嫌気的、嫌気性
analgesic 鎮痛剤
analog アナログ、類似物
analytical sample 分析用サンプル
anchimeric assistance 隣接基関与（neighboring group participation)
anesthetic 麻酔薬
anhydride 無水物
anilide アニリド
anion アニオン、陰イオン
anionic　 アニオンの、陰イオンの
anisotropy 異方性
annelation 環化
annulation 環化
annulene アヌレン
anode 陽極
anomer アノマー
anomeric effect アノマー効果
ansa compounds アンサ化合物
antagonist アンタゴニスト、拮抗薬、遮断薬
antarafacial アンタラ型
anthocyanin アントシアニン
anthracene アントラセン
anthraquinone アントラキノン
anti アンチ
antiaromaticity 反芳香族性
antibiotic 抗生物質
antibody 抗体
antigen 抗原
anti-Markownikoff addition 反マルコフニコフ付加
antimony アンチモン Sb
antiperiplanar アンチペリプラナー
antipodes 対掌体
apoptosis アポトーシス、計画細胞死、プログラム細胞死
aprotic solvents 非プロトン溶媒
aqueous 水の、水のような
Arbuzov reaction アルブゾフ反応
arene アレーン、芳香族炭化水素
argentic 銀の（cf. argentic chloride 塩化銀）
arginine アルギニン
argon アルゴン Ar
Arndt-Eistert synthesis アルント・アイステルト合成
aromatic compound 芳香族化合物
aromaticity 芳香属性
Arrhenius equation アレニウス式
arrow-pushing mechanism 矢印を使った反応機構
arsenic 砒素 As
arsines アルシン AsH3
aryl groups アリール基
aryne アライン
asparagine アスパラギン
aspartic acid アスパラギン酸
aspirator アスピレーター、水流ポンプ
assay 試験、分析
asymmetric induction 不斉誘起
asymmetric synthesis 不斉合成
asymmetry 不斉、非対称
atmosphere 大気、空気、雰囲気
atmospheric pressure 大気圧
atomic orbital 原子軌道
atomic weight 原子量
atropisomer アトロプ異性体、回転異性体
auric chloride 塩化金 AuCl3
autocatalytic reaction 自己触媒反応
autoxidation 自動酸化
Avogadro constant アボガドロ定数
axial アキシャル、軸上の
axis of helicity らせん軸
azane アザン NH3
azide アジド -N3
aziridine アジリジン
azlactone アズラクトン
azo compounds アゾ化合物 R-N=N-R'
azomethine ylide アゾメチンイリド
azoxy compounds アゾキシ化合物
- B -
9-BBN 9-ボラビシクロ［3.3.1］ノナン
Baeyer-Villiger Oxidation バイヤー・ビリガー反応
Baldwin's rules ボールドウィン則
Bamberger rearrangement バンバーガー転位
Bamford-Stevens reaction バンフォード・スティーブンス反応
Barbier reaction バルビエ反応
Barbier-Wieland degradation バルビエ・ビーラント分解
barbiturates バルビツール酸類
barium バリウム Ba
Barton reaction バートン反応
Barton-McCombie reaction　 バートン・マッコンビー反応
base peak 基準ピーク、ベースピーク
basicity 塩基度
bathochromic shift 深色移動、長波長シフト、レッドシフト
Beckmann rearrangement ベックマン転位
benzaldehyde ベンズアルデヒド PhCHO
benzene ベンゼン C6H6
benzeneselenenyl chloride 塩化ベンゼンセレネニル PhSeCl
benzenethiol ベンゼンチオール、チオフェノール C6H5SH
benzilic acid rearrangement ベンジル酸転位
benzoic acid 安息香酸 PhCO2H
benzoin condensation ベンゾイン縮合
benzophenone ketyl ベンゾフェノンケチル
benzoquinone ベンゾキノン
benzotriazole ベンゾトリアゾール
benzoyl chloride 塩化ベンゾイル PhCOCl
benzyl ベンジル
benzyl chloroformate クロロギ酸ベンジル PhCH2OCOCl
benzylamine ベンジルアミン PhCH2NH2
benzyne ベンザイン
Bergman reaction バーグマン反応
beryllium ベリリウム Be
betaine ベタイン
β-lactam ベータラクタム、β-ラクタム
bias バイアス、偏り、偏見
bicyclic compound 二環式化合物
Biginelli reaction ビジネリ反応
bilayer 二層膜
binaphthol ビナフトール
bioactive 生物活性
bioassay 生物評価法、生物試験、バイオアッセイ
biocatalyst 生物触媒、生体触媒
bioconjugate バイオコンジュゲート
biomimetic synthesis バイオミメティック合成
biosynthesis 生合成
biotechnology バイオテクノロジー
biotin ビオチン
biphenyl ビフェニル
Birch reduction バーチ還元
Bischler-Napieralski reaction ビシュラー・ナピーラルスキー反応
bismuth ビスマス Bi
boat conformer ボート型立体配座
boiling point 沸点
Boltzmann distribution ボルツマン分布
bond dissociation energy 結合解離定数
bond order 結合次数
borane ボラン BH3
boron ホウ素 B
boronic acid ボロン酸 R-B(OH)2
Bouveault-Blanc reduction ブーボー・ブラン還元
Bredt's rule ブレット則
bridgehead 橋頭堡、ブリッジヘッド
bromination ブロム化、臭素化
bromine 臭素 Br
bromohydrin　 ブロモヒドリン
bromonium ion ブロモニウムイオン
Bronsted acid ブロンステッド酸
Brook rearrangement ブルック転位
Bucherer reaction　 ブヒャラー反応
Buchwald-Hartwig aryl amination バックワルド・ハートウィッグアリールアミノ化反応
Bürgi-Dunitz trajectory ビュルギ・ドゥニッツ軌道（軌跡）
Bunsen burner ブンゼンバーナー
butadiene　 ブタジエン
butane ブタン CH3-CH2-CH2-CH3
n-butane
- C -
cadmium カドミウム Cd
caffeine カフェイン
cage effect かご効果、ケージ効果
calcium カルシウム Ca
calibration 補正、校正、較正
calixarenes カリクサレン
calorimetry 　 熱量測定
camphor　 樟脳、カンファー
camphorsulfonic acid (CSA) カンファースルホン酸
Cannizzaro reaction カニッツアロ反応
canonical structure 極限構造式
capillary column キャピラリーカラム
caprolactam カプロラクタム
captodative effect キャプトデイティブ効果
carbamate カルバマート、カルバメート
carbanion カルバニオン、カルボアニオン
carbene カルベン R2C:
carbenium ion カルベニウムイオン R3C+
carbenoid カルベノイド
carbinol カルビノール R-CH2OH
carbinolamine カルビノールアミン
carbobenzoxy (Cbz) カルボベンゾキシ、ベンジルオキシカルボニル基
carbocation カルボカチオン
carbocyclic compounds 炭素環式化合物
carbodiimide カルボジイミド R-N=C=N-R
carbohydrate 炭水化物
carbon 炭素 C
carbon dioxide 二酸化炭素 CO2
carbon electrode 炭素電極
carbonium ion カルボニウムイオン
carbonyl absorption カルボニル（基）吸収
carbonyl compound カルボニル化合物
carbonyldiimidazole (CDI) N,N'-カルボニルジイミダゾール
carboranes カルボラン
carboxamide カルボキサミド R-CONR'R"
carboxylic acid カルボン酸 R-CO2H
carcinogen 発がん物質
carotenes カロチン
carotenoids カロテノイド
carrier gas キャリヤーガス（ガスクロマト）
Carroll rearrangement キャロル転位
carvone カルボン
cascade reaction カスケード反応
Castro-Stephens coupling カストロ・スティーブンスカップリング
catalase カタラーゼ
catalysis 触媒作用
catalyst 触媒
catalytic hydrogenation 接触還元
catalytic poison 触媒毒
catecholamine カテコールアミン
catecholborane カテコールボラン
catenanes カテナン
cathode 陰極
cation カチオン
cationic カチオンの
cellulose セルロース
Celsius temperature 摂氏温度
centrifugation 遠心分離
cephalosporin セファロスポリン
cerium セリウム Ce
cesium　 セシウム Cs
chain initiation 連鎖開始反応
chain reaction 連鎖反応
chair conformer イス型配座
chalcone カルコン
charge separation 電荷分離
charge-transfer complex 電荷移動錯体
chelate キレート
chelation control キレーションコントロール
chelation effect キレート効果
cheletropic reaction ケロトロピー反応
chemical shift 化学シフト
chemiluminescence 化学発光、化学ルミネセンス
chemoselectivity　 化学選択性、官能基選択性
chemotherapy 化学療法
Chichibabin reaction チチバビン反応
chiral auxiliary キラル補助基、不斉補助基
chiral center キラル中心
chirality キラリティー
chirotopic キラルな（環境にある）原子、基、面など
chloral クロラール CCl3CHO
chloramine クロラミン
chloramine T クロラミン-T
chlorination 塩素化、クロル化
chlorine 塩素 Cl
chloroform クロロホルム CHCl3
chlorohydrins クロロヒドリン
chlorotrimethylsilane クロロトリメチルシラン Me3SiCl
cholesterol コレステロール
cholic acid コール酸
chromatogram クロマトグラム
chromatograph クロマトグラフ
chromatographic purification クロマトによる精製
chromatography　 クロマトグラフィー
chromium クロム Cr
chromophore 発色団
chromosome 染色体
chronic toxicity 慢性毒性
Chugaev reaction チュガエフ反応
cinnamyl alcohol シンナミルアルコール
circular dichroism 円二色性
cisoid conformation シソイド配座、シス様配座
citral シトラール
citric acid クエン酸
Claisen condensation クライゼン縮合
Claisen rearrangement クライゼン転位
Claisen-Schmidt condensation クライゼン・シュミット反応
Clemmensen reaction クレメンセン反応（還元）
coacervation コアセルベーション
coagulation 凝結、凝析
cobalt コバルト Co
cocaine コカイン
coefficient 係数
coenzyme 補酵素
cofactors 補因子、補助因子、コファクター
collagen コラーゲン
colloid コロイド
colloidal コロイドの、コロイド様
colloidal dispersion コロイド分散系、コロイド
colorimeter 熱量計、カロリメーター
column chromatography カラムクロマトグラフィー
combustion 燃焼
competition 競争
computational chemistry 計算化学
computer-assisted drug design (CADD) コンピューター支援薬物設計
concave face 凹面(形)の、コンケーブ面
concentration 濃度
concerted process 協奏的過程
concertedness 協奏性
condensation reaction 縮合反応
conductivity 伝導度
configuration 配置
configurational isomer 配置異性体（幾何異性体や光学異性体など）
configurations of metal complexes 金属錯体の配置
conformation 配座、コンフォメーション
conformational analysis （立体）配座解析
conformational isomer 配座異性体
conformer 配座異性体
congener 同族体
conjugate addition 共役付加
conjugated dienes 共役ジエン
conjugation 共役
connectivity 連結性、接続性
conrotatory 共旋的
constitutional isomers 構造異性体
contaminated 汚染された
contamination 汚染
convergent synthesis 収束的合成
convex face 凸面、コンベックス面
coordination number 配位数
Cope elimination コープ脱離
Cope rearrangement コープ転位
copolymer 共重合体、コポリマー
copper 銅 Cu
corannulene コラヌレン
Corey-Bakshi-Shibata reduction (CBS) コーリー・バクシ・柴田還元
Corey-Fuchs reaction コーリー・フクス反応
Corey-Kim oxidation コーリー・キム酸化
Corey-Winter olefin synthesis コーリー・ウィンターのオレフィン合成法
Cornforth rearrangement コンフォース転位
correlation diagram 相関図
corrosion 腐食
cortisone コーチゾン
cosolvent 共溶媒
COSY コージー
coumarin クマリン
counter-current flow 対向流
coupling constant 結合定数、カップリング定数
covalent bond 共有結合
Cram's rule クラム則
cresol クレゾール
Criegee reaction クリーゲー反応
criteria 規範、判定基準
critical temperature 臨界温度
cross-conjugation 交差共役
crossed aldol reactions 交差アルドール反応
crosslink 架橋結合、クロスリンク
crotyl bromide 臭化クロチル、クロチルブロミド
crown ether クラウンエーテル
cryogenic 低温の
cryptand クリプタンド
cryptate クリプテート、クリプタンド錯体
crystallinity 結晶化度
crystallization 結晶化
cumene　 クメン
cumulated diene 累積二重結合 (cumulative double bond)
cumulative examination (cume) キューム（学位取得資格を得るための（通常）月一度の試験）
cumulenes クムレン
curriculum vitae (CV) 履歴（書）（vitaともいう）
Curtius rearrangement クルチウス転位
curved arrows 曲線矢印（反応機構に用いる）
cyanogen bromide シアノゲンブロミド、臭化シアン BrCN
cyanohydrin シアンヒドリン
cyclic compound 環状化合物
cyclization 環化
cycloaddition 環状付加
cycloadduct 環状付加体
cycloalkanes シクロアルカン
cyclodepsipeptides シクロデプシペプチド
cyclodextrins シクロデキストリン
cyclohexane シクロヘキサン
cyclohexyl シクロヘキシル
cyclooctadiene シクロオクタジエン
cyclooctatetraene シクロオクタテトラエン
cyclopentadiene シクロベンタジエン
cyclopentadienyl シクロペンタジエニル
cyclophanes シクロファン
cyclopropanation シクロプロパン化
cyclopropane シクロプロパン
cycloreversion 環開裂
cyclotron サイクロトロン
cysteine システイン
cystine シスチン
cytochrome P450 チトクローム P450
cytosine シトシン
cytotoxicity 細胞毒性
- D -
1,3-dipolar cycloaddition 1,3-双極子付加
1,4-diazabicyclo[2.2.2]octane (DABCO) 1,4-ジアザビシクロ[2.2.2]オクタン
1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) 1,8-ジアザビシクロ[5.4.0]-7-ウンデケン
2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) 2,3-ジクロロ-5,6-ジシアノ-1,4-ベンゾキノン
Dakin reaction　 デーキン反応
Darzens condensation ダルツェンス縮合
de Mayo reaction　 デ・マヨ反応
deactivation　 不活性化
deacylation 脱アシル化
dead-volume (in chromatography) 死容積、デッドボリューム
dealkylation 脱アルキル化
deamination 脱アミノ化
decalin デカリン
decarboxylation 脱炭酸
decomposition 分解
degree Celsius 摂氏
degree Fahrenheit 華氏
dehydration 脱水
dehydrogenase　 脱水素化酵素、デヒドロゲナーゼ
Delepine reactions デレピン反応
delocalization 非局在化
Demjanov rearrangement デミヤノフ転位
denaturation 変成
dendrimer デンドリマー
deoxygenation 脱酸素化
deoxyribonucleic acids (DNA) デオキシリボ核酸
depsipeptides デプシペプチド
derivative 誘導体
deshielding effect デシールディング効果、非遮蔽効果
desiccant　 乾燥剤
desilylation 脱シリル化
Dess-Martin periodinane デス・マーチン・ペルヨージナン
detergent 洗剤
deuterated solvent 重溶媒
deuterium 重水素
deviation 偏差
dextrins デキストリン
dextrorotatory 右旋性
dialysis 透析
diamond structure ダイアモンド構造
diastereoisomerism ジアステレオ異性
diastereomer ジアステレオマー、ジアステレオ異性体
diastereomeric excess ジアステレオマー過剰率（d.e.）
diastereomeric ratio ジアステレオマー比
diastereoselectivity ジアステレオ選択性
diastereospecificity ジアステレオ特異性
diastereotopic ジアステレオトピック
diazirine ジアジリン
diazoketone　 ジアゾケトン
diazomethane ジアゾメタン CH2N2
diazonium salt　 ジアゾニウム塩 Ar-N2+X-
DIBAL 水素化ジイソブチルアルミニウム i-Bu2AlH
diborane ジボラン H3BBH3
dibutyltin oxide ジブチルスズオキシド n-Bu2SnO
dichlorocarbene　 ジクロロカルベン Cl2C:
dichlorodicyanobenzoquinone (DDQ) DDQ、ジクロロジシアノベンゾキノン
dichloromethane ジクロロメタン、メチレンクロリド CH2Cl2
dicyclohexylcarbodiimide (DCC) ジシクロヘキシルカルボジイミド
Dieckmann condensation ディークマン縮合
dielectric constant 誘電定数、比誘電率
Diels-Alder reaction ディールス・アルダー反応
diene ジエン
dienone-phenol rearrangement ジエノン-フェノール転位
dienophile　 ジエノフィル、親ジエン
diethyl azodicarboxylate (DEAD) ジエチルアゾカルボキシラート、アゾジカルボン酸ジエチル EtO2C-N=N-CO2Et
diethyl malonate マロン酸ジエチル
diethyl tartrate 酒石酸ジエチル
diethylaluminum chloride ジエチルアルミニウムクロリド Et2AlCl
diethylzinc ジエチル亜鉛 Et2Zn
diffraction 回折
diffusion 拡散
diffusion-controlled rate 拡散律速速度
diglyme ジグリム (MeOCH2CH2)2O
dihalide　 ジハライド
dihedral angle 二面角
diimide ジイミド HN=NH
diisobutylaluminum hydride 水素化ジイソブチルアルミニウム i-Bu2AlH
diisopropylethylamine (Hünig's base) N,N-ジイソプロピルエチルアミン、ヒューニッヒ塩基 i-Pr2NEt
diketene　 ジケテン
dilute solution 希釈溶液
dimer ダイマー、二量体
dimerization 二量化
dimethoxyethane ジメトキシエタン、グライム MeOCH2CH2OMe
dimethyl dioxirane (DMDO) ジメチルジオキシラン
dimethyl malonate マロン酸メチル
dimethyl sulfide ジメチルスルフィド Me2S
dimethyl sulfoxide (DMSO) ジメチルスルホキシド
dimethylformamide (DMF) ジメチルホルムアミド
dimethylsulfonium methylide ジメチルスルホニウムメチリド
Dimroth rearrangement ジムロート転位
dinitrobenzenesulfonyl chloride ジニトロベンゼンスルホニルクロリド
dinitrophenylhydrazone (DNP) ジニトロフェニルヒドラゾン
dioxane ジオキサン
dioxin ダイオキシン
diphenyl disulfide ジフェニルジスルフィド PhS-SPh
diphenyl phosphorazidate (DPPA)
dipolar cycloaddition 双極子（環状）付加
dipole　 双極子、ダイポール
dipole moment 双極子モーメント
directed aldol reaction （指向した？）アルドール反応
directed ortho metalation （指向した？）オルトメタル化
disaccharides 二糖類
disiamylborane ジシアミルボラン
dispenser ディスペンサー
dispersion 分散
disrotatory 逆旋的
dissociation energy 解離エネルギー
dissolution 溶解
dissolving metal reduction 溶解金属還元
dissymmetry 非対称
diterpenoids ジテルペノイド
dithiane　 ジチアン
docking studies ドッキング解析
donor　 供与体、ドナー
double helix　 二重らせん
Duff reaction ダフ反応
dye pigments 染料顔料、染料色素
dynamic range 動的範囲
- E -
1,2-ethanediol 1,2-エタンジオール、エチレングリコール HOCH2CH2OH
eclipsed conformer 重なりコンフォマー
Edman degradation エドマン分解
effective charge　 有効電荷
effective molarity 有効モル濃度
effectiveness 有効性、効力
effluent 流出液（液クロの）
eicosanoids エイコサノイド
eighteen-electron rule １８電子則
electric current 電流
electrochemiluminescence 電気化学発光
electrocyclic reaction 電子環状反応
electron 電子
electron microscopy 電子顕微鏡
electron spin resonance (EPR) 電子スピン共鳴
electron transfer 電子移動
electron-donating group 電子供与基
electronegativity 電気陰性度
electronic effect 電子効果
electronic excitation 電子励起
electronically excited state 電子励起状態
electron-withdrawing group 電子求引基
electrophile 求電子剤
electrophilic substitution 親電子置換反応
electrophilicity 求電子性
electrophoresis　 電気泳動
electrostatic 静電（気）の
element 元素、要素
elimination reaction 脱離反応
eluate 溶出液
eluent 溶離液、溶離剤
elution 溶出
empirical formula 実験式
empirical rule 実験則
emulsion　 エマルジョン、懸濁液
enamide エナミド
enamine エナミン
enantioenriched enantiomerically enriched（片方の鏡像異性体に富んだ）
enantiomer 鏡像異性体
enantiomeric excess 鏡像体過剰率
enantiomeric purity　 光学純度
enantiomorph 鏡像、鏡像体
enantioselective reduction エナンチオ選択的還元、不斉還元
enantioselectivity エナンチオ選択性
enantiospecific エナンチオ特異性
enantiotopic エナンチオトピック
encapsulation カプセル化
endo effect エンド効果
endo-exo ratio エンド-エキソ比
endothermic 吸熱の
ene reaction　 エン反応
enediyne　 エンジイン
energetics エネルギー論
energy エネルギー
energy of activation 活性化エネルギー
energy profile エネルギープロフィール
enol ether　 エノールエーテル
enolate　 エノラート
enolate anion エノラートアニオン
enolization エノール化
enols エノール
enone エノン
enthalpy エンタルピー
entropy エントロピー
enyne エンイン
enzyme 酵素
ephedrine エフェドリン
epichlorohydrin　 エピクロロヒドリン
epimer エピマー
epimerization エピマー化
epoxidation エポキシ化
epoxide　 エポキシド
equatorial　 エクアトリアル、赤道
equilibration 平衡
equilibrium constant 平衡定数
equivalent 等価（の）
Erlenmeyer-Plochl azlactone and amino acid synthesis エルレンマイヤーのアミノ酸合成法
erythro, threo エリトロ、トレオ
Eschenmoser fragmentation エシェンモーザーフラグメンテーション
Eschenmoser's salt エシェンモーザー塩
Eschweiler-Clarke reaction エッシュワイラー・クラーク反応
essential amino acids 必須アミノ酸
ester エステル R-CO2R'
ester cleavage エステル開裂
esterification エステル化
ethane エタン CH3-CH3
ethanol エタノール、エチルアルコール C2H5-OH
ether　 エーテル R-O-R'
ethyl acetate 酢酸エチル AcOEt
ethyl acetoacetate アセト酢酸エチル MeCOCH2CO2Et
ethyl diazoacetate ジアゾ酢酸エチル N2=CHCO2Et
ethylene glycol エチレングリコール HOCH2CH2OH
europium ユーロピウム Eu
evaporation 蒸発
exchange reaction 交換反応
excitation 励起
excited state 励起状態
exclusion chromatography 排除クロマトグラフィー
exo, endo エキソ、エンド
exocyclic 環外（の）
exothermic reaction 発熱反応
extinction coefficient 吸光係数、消散係数
extraction 抽出
- F -
fast-atom bombardment (FAB) mass spectroscopy 高速原子衝撃質量分析計
fatty acids 脂肪酸
Favorskii rearrangement ファボルスキー転位
Felkin-Anh model　 フェルキン・アンモデル
Fenton reaction フェントン反応
fermentation 醗酵
ferric chloride 塩化鉄 (III) FeCl3
ferrocenes フェロセン
field desorption (in mass spectrometry) 電解脱離質量分析計
filtration ろ過
fingerprint region 指紋領域（IR）
Finkelstein reaction フィンケルシュタイン反応
Fischer carbene フィッシャーカルベン
Fischer esterification フィッシャーエステル合成法
Fischer indole synthesis フィッシャーインドール合成法
Fischer projection formula フィッシャー投影式
five-membered ring 五員環
flame ionization detector (in gas chromatography) 水素炎イオン化検出器
flash chromatography フラッシュクロマトグラフィー
flash photolysis 閃光光分解
flash point 引火点
flash vacuum pyrolysis (FVP) 瞬間真空熱分解法
flavins フラビン
flavonoids (isoflavonoids and neoflavonoids) フラボノイド（イソフラボノイド、ネオフラボノイド）
fluidity 流動度
fluoresceins フルオレセイン
fluorescence 蛍光
fluorine フッ素 F
fluorocarbons フッ化炭素
force constant 力の定数
force-field calculation 力場計算
formal charge 形式電荷
formaldehyde ホルムアルデヒド HCHO
formic acid ギ酸 HCO2H
fossil fuel 化石燃料
Fourier transform spectrometer フーリエ変換分光計
four-membered rings 四員環
fractionation 分画
fragment ion フラグメントイオン
fragmentation フラグメンテーション、フラグメント化
free energy of activation 活性化自由エネルギー
free induction decay (FID) 自由誘導減衰
free radical フリーラジカル
free radical bromination フリーラジカルブロム化
free rotation 自由回転
Fremy's salt フレミー塩
frequency 周波数
Friedel-Crafts acylation フリーデル・クラフツアシル化反応
Friedel-Crafts reaction フリーデル・クラフツ反応
Friedlaender synthesis フリードレンダー合成
Fries rearrangement フリース転位
frontier orbitals フロンティア軌道
FT spectroscopy フーリエ変換分光学
fullerenes フラーレン
fulvene フルベン
fumaric acid フマル酸
fume hood ドラフトチャンバー
functional group 官能基
functionality 官能基
functionalized 官能基化（された）
furan フラン
furanoses フラノース
- G -
Gabriel synthesis ガブリエル合成
gadolinium ガドリニウム Gd
gallium ガリウム Ga
gas chromatography (GC) ガスクロマトグラフィー
Gattermann-Koch reaction ガッターマン・コッホ反応
gauche conformation ゴーシュ配座
gel permeation chromatography ゲル浸透クロマトグラフィー
geminal ジェミナル
gene amplification 遺伝子増幅
genome 　 ゲノム
genomics ゲノム学、ゲノミックス、ジェノミックス
geometrical isomers 幾何異性体
germanium ゲルマニウム Ge
Gilman reagent ギルマン試薬
glove box グローブボックス
glucose グルコース（ブドウ糖）
glutamic acid グルタミン酸
glutamine グルタミン
glutaric acid グルタル酸
glycals グリカール
glycans グリカン（多糖（類））
glycerides グリセリド
glycine グリシン
glycoconjugate 複合糖質
glycol グリコール
glycol cleavage グリコール開裂
glycolipids 糖脂質
glycon グリコン部
glycoproteins 糖タンパク質
glycoside 配糖体
glycosylamines グリコシルアミン
glycosylation グリコシル化
gold　 金 Au
gradient elution (in chromatography) 勾配溶離
graphite グラファイト、黒鉛
Grignard reaction グリニャール反応
Grob fragmentation グロブフラグメンテーション
ground state 基底状態
Grubbs olefin metathesis グラッブスオレフィンメタセシス反応
guanine グアニン
guanidine　 グアニジン
- H -
hafnium ハフニウム Hf
halobenzene　 ハロベンゼン、ハロゲン化ベンゼン
haloform reaction　 ハロホルム反応
halogen ハロゲン
halogenation ハロゲン化
halohydrins ハロヒドリン
halonium ion ハロニウムイオン
hamiltonian operator ハミルトン演算子
Hammett constants ハメット定数
Hammett equation ハメット式
Hantzsch pyridine synthesis ハンチュのピリジン合成法
hapten ハプテン
Haworth formula ハワース式投影式
head-to-head polymerization 頭-頭重合
head-to-tail polymerization 頭-尾重合
heat of formation 生成熱
heat of hydrogenation 水素付加熱
heavy atom isotope effect 重原子同位体効果
Heck reaction (Mizoroki-Heck reaction) ヘック反応（溝呂木・ヘック反応）
helical structure らせん構造
helicenes ヘリセン
helicity ヘリシティー、らせん構造
helium　 ヘリウム He
helix らせん構造
Hell-Volhard-Zelinsky reaction ヘル・フォルハルト・ゼリンスキー反応
hemiacetal ヘミアセタール
hemiaminal ヘミアミナール
hemiketal ヘミケタール
Henry reaction ヘンリー反応
heterobimetallic complex ヘテロ二核金属錯体
heterocycles 複素環
heterocyclic compounds 複素環式化合物
heterogeneous catalysis 不均一系触媒反応
hexamethyldisilazane　 ヘキサメチルジシラザン
hexamethylenetetramine ヘキサメチレンテトラミン、ヘキサミン
hexamethylphosphoramide ヘキサメチルリン酸トリアミド
hexyne ヘキシン
high-pressure mercury lamp 高圧水銀灯
hindered rotation 束縛回転
histidine ヒスチジン
Hofmann elimination ホフマン脱離
Hofmann reaction ホフマン反応
Hofmann-Loffler-Freytag reaction ホフマン・ロフラー・フライターク反応
highest occupied molecular orbital (HOMO) 最高被占軌道
homochiral ホモキラル
homoenolate ホモエノラート
homogeneous catalysis 均一触媒反応
homologation ホモログ化
homology ホモロジー
homolytic cleavage 均一開裂、ホモリシス
Horner-Wadsworth-Emmons reaction ホルナー・ワズワース・エモンズ反応
Hosomi-Sakurai reaction 細見・桜井反応
host　 ホスト、宿主
Hückel rule ヒュッケル則
Huisgen cycloaddition ヒュイズゲン環化付加反応
Hund rules フント則
Hunsdiecker reaction フンスディーカー反応
hybrid orbital 混成軌道
hybridization 混成
hydration 水和
hydrazide ヒドラジド
hydrazine ヒドラジン H2NNH2
hydrazone ヒドラゾン R2C=NNH2
hydroboration ヒドロホウ素化
hydrocarbons 炭化水素
hydrogen 水素 H
hydrogen bonding 水素結合
hydrogen peroxide 過酸化水素 H2O2
hydrogenate 水素化する
hydrogenation 水素化
hydrolysis 加水分解
hydroperoxide ヒドロペルオキシド R-OOH
hydrophilic 親水性の
hydrophilicity 親水性
hydrophobic 疎水性の
hydrophobicity 疎水性
hydroxamic acid ヒドロキサム酸
hydroxide 水酸化物イオン
hydroxylamine ヒドロキシルアミン
hydroxylation ヒドロキシル化
hyperconjugation 超共役
hypervalent iodine compound 超原子価ヨウ素化合物
hypothesis 仮説、仮定
hysteresis ヒステリシス（履歴現象）
- I -
4-isopropyl-2-oxazolidinone 4-イソプロピル-2-オキザジリノン
ideal gas 理想気体
identification 同定
imidazole イミダゾール
imide イミド
imine イミン
iminium ether イミニウムエーテル
iminium ion イミニウムイオン
immobilized phase (in chromatography) 固定層
immunochemistry 免疫化学
impregnation (in chromatography) 飽和させる、充満させる、しみ込ませる
impurity　 不純物
in situ　 インシトゥ
in vacuo 真空中で
in vitro インビトロ
in vivo インビボ
incinerator 焼却炉
inclusion complex 包接錯体
indicator 指示薬
indium インジウム In
indole インドール
indolocarbazole インドロカルバゾール
induction period 誘導期
inductive effect 誘起効果
inert gas 不活性気体
infrared spectroscopy 赤外分光法
inhibition 阻害
inhibitor 阻害剤
inhibitory concentration (IC) 阻害濃度
initiation 開始
initiator 開始剤、重合開始剤
inositols イノシトール
inseparable mixture　 分離不可能な混合物
insertion 挿入
insulin　 インシュリン
intercalation 層の間に挿入する
interconversion 相互変換
interface インターフェイス
intermediate 中間体
intermolecular reaction 分子間反応
internal standard (in chromatography) 内部標準
intersystem crossing 項間交差
intimate ion pair 緊密イオン対
intramolecular reaction 分子内反応
intrinsic barrier 内在的な障壁、固有障壁
inversion 反転
iodine ヨウ素 I
iodoacetonitrile ヨウ化アセトニトリル ICH2CN
iodobenzene ヨウ化ベンゼン C6H5-I
iodobenzene diacetate （ジアセトキシヨード）ベンゼン PhI(OAc)2
iodoform ヨードホルム CHI3
iodoform reaction ヨードホルム反応
iodolactonization ヨードラクトン化反応
iodomethane ヨードメタン、ヨウ化メチル CH3-I
iodometric titration ヨウ素還元滴定
iodonium ion ヨードニウムイオン
iodosobenzene ヨードソベンゼン PhI+O-
iodosylbenzene ヨードシルベンゼン（ヨードソベンゼン） PhI+O-
ion イオン
ion pair イオン対
ion-exchange chromatography イオン交換クロマトグラフィー
ion-exchange resins イオン交換樹脂
ionic bonding イオン結合
ionic liquid　 イオン液体、イオン性液体
ionic reaction イオン反応
ionization potential イオン化ポテンシャル
ionophore イオノホア
ipso-attack イプソ攻撃（cf. ipso substitution)
Ireland-Claisen Rearrangement アイルランド・クライゼン転位
iridium イリジウム Ir
iridium catalysts イリジウム触媒
iridoids イリドイド
iron 鉄 Fe
irradiation 照射
irreversible reaction 不可逆反応
isoamyl nitrite 亜硝酸イソアミル
isobutene イソブテン
isobutyl chloroformate クロロギ酸イソブチル
isobutyraldehyde イソブチルアルデヒド (CH3)2CH-CHO
isobutyronitrile イソブチロニトリル (CH3)2CH-CN
isobutyryl chloride 塩化イソブチリル
isocoumarin イソクマリン
isocyanate イソシアナート R-N=C=O
isocyanic acid イソシアン酸 H-N=C=O
isocyanide イソシアニド、イソニトリル R-NC
isocyanuric chloride イソシアヌル酸塩化物
isoelectric point 等電点
isoelectronic 等電子的
isoleucine　 イソロイシン
isomer 異性体
isomerase イソメラーゼ、異性化酵素
isomeric 異性体の
isomerism 異性
isomerization 異性化
isonitrile イソニトリル R-NC
isopinocamphenylborane イソピノカンフェニルボラン
isoprene rule イソプレン則
isoprenes イソプレン
isoprenoid イソプレノイド、テルペン
isopropanol イソプロパノール i-PrOH
isopropenyl acetate 酢酸イソプロペニル
isopropyl bromide 臭化イソプロピル i-PrBr
isopropylamine イソプロピルアミン (CH3)2CH-NH2
isopropylidene malonate
Me2C=C(CO2R)2
isoquinoline　 イソキノリン
isothiocyanate イソチオシアナート R-N=C=S
isotope effect 同位体効果
isotopic abundance 同位体存在度
isourea イソ尿素、イソウレア
isovaleraldehyde イソバレルアルデヒド
isovanillin イソバニリン
isoxazole イソオキサゾール
itaconic anhydride 無水イタコン酸
Ito-Saegusa oxidation 伊藤・三枝酸化
- J -
Japp-Klingemann reaction ヤップ・クリンゲマン反応
Jones oxidation ジョーンズ酸化
Julia olefination ジュリアオレフィン合成法
Julia-Kocienski olefination ジュリア・コチンスキーオレフィン合成法
- K -
KAPA potassium 3-aminopropylamide H2N(CH2)3-NHK
Karl Fischer reagent カールフィッシャー試薬
kelvin ケルビン
ketal　 ケタール
ketene　 ケテン R2C=C=O
ketene acetals ケテンアセタール R2C=C(OR')2
ketenimine ケテンイミン R2C=C=NR'
ketimine ケチミン R2C=NR'
keto ケト
ketone　 ケトン R2C=O
ketoxime ケトオキシム、ケトンオキシム R2C=NOH
ketyl ケチル
Kiliani reagent キリアニ試薬 Na2Cr2O7/dil. H2SO4
kinetic acidity 速度論的酸性度
kinetic control　 速度支配
kinetic resolution 速度論的分割
Knoevenagel condensation （又は） クネベナーゲル縮合
Knorr quinoline synthesis (又は) クノルのキノリン合成法
Kochi reaction コチ反応（Kochi先生は日系米国人）
Kolbe electrolytic synthesis コルベ電解反応
Kolbe-Schmitt reaction コルベ・シュミット反応
Krapcho decarbalkoxylation クラプチョの脱カルボアルコキシル化反応
krypton クリプトン Kr
K-Selectride K-セレクトライド KBH(s-Bu)3
Kumada coupling 熊田カップリング
- L -
labeling　 ラベル付け、標識付け
labile　 不安定な、変化しやすい
labile intermediate 不安定な中間体
laboratory sample 実験室試料
lachrymator 催涙物質
lactam ラクタム
lactic acid 乳酸
lactim ラクチム
lactol ラクトール
lactone ラクトン
lactonization ラクトン化
lag phase 潜伏期、遅延期
lanthanide alkoxides ランタニドアルコキシド
lanthanum ランタン La
laser レーザー
latent　 隠れた、見えない
Lawesson's reagent ローソン試薬
LD50 50% 致死量
LDA リチウムジイソプロピルアミド LiNiPr2
lead　 鉛 Pb
lead tetraacetate (LTA) 四酢酸鉛 Pb(OAc)4
leaving group 脱離基
Lemieux-Johnson oxidation レミュー・ジョンソン酸化
lethal dose 致死量
leucine　 ロイシン
Leuckart reaction ロイカルト反応
leukotrienes ロイコトリエン
levulinic acid レブリン酸 CH3COCH2CH2CO2H
Lewis acids ルイス酸
ligand 配位子、リガンド
lignans リグナン
lignins リグニン
Lindlar's catalyst リンドラー触媒 Pd/CaCO3 - Pb(OAc)2
line width 線幅
linear synthesis 直線的合成
lipase　 リパーゼ
lipids 脂質
lipophilic 親油的
lipophilicity 親油性
lipoproteins リポタンパク質
liposome リポソーム
liquid ammonia　 液体アンモニア
liquid chromatography (LC) 液体クロマトグラフィー
liquid crystal 液晶
lithium リチウム Li
lithium acetate 酢酸リチウム LiOAc
lithium acetylide リチウムアセチリド HC≡CLi
lithium aluminum hydride (LAH) 水素化アルミニウムリチウム LiAlH4
lithium chloride 塩化リチウム LiCl
lithium diisopropylamide (LDA) リチウムジイソプロピルアミド LiNiPr2
lithium hexamethyldisilazide (LHMDS)
LiN(SiMe3)2
lithium iodide ヨウ化リチウム LiI
lithium perchlorate (LiClO4) 過塩素酸リチウム LiClO4
lithium tri-tert-butoxyaluminohydride ヒドリドトリス（t-ブトキシ）アルミン酸リチウム LiAl(OtBu)3H
lone pair 孤立電子対、非共有電子対
Lossen rearrangement ロッセン転位
Luche reduction　 ルーシュ還元 NaBH4-CeCl3･7H2O
luminescence ルミネセンス
lowest unoccupied molecular orbital (LUMO) 最低空軌道
lysine リシン
- M -
2-mercaptoethanol 2-メルカプトエタノール HS-CH2CH2-OH
macrocycle 大員環
macrolides マクロライド
macromolecule 巨大分子、高分子
magic acid マジック酸、超強酸 H2SO3F+
(SbF5とFSO3Hを混ぜる)
magnesium　 マグネシウム Mg
magnesium amalgam マグネシウムアマルガム Mg-Hg
magnesium bromide 臭化マグネシウム MgBr2
main group metals 典型金属元素
maleic anhydride 無水マレイン酸
malic acid リンゴ酸
malonic acid マロン酸
malonic ester synthesis マロン酸エステル合成法
malononitrile マロンニトリル
mandelic acid マンデル酸
manganese マンガン Mn
manganese dioxide 二酸化マンガン MnO2
Mannich reactions マンニッヒ反応
mannose マンノース
Markownikoff rule マルコフニコフ則
mass balance 物質収支
mass spectrometer　 質量分析計
mass spectrometry 質量分析法
mass spectrum 質量スペクトル
material safety data sheet (MSDS) 製品安全データシート
matrix isolation　 マトリックス分離
McFadyen-Stevens reaction マックファジエン・スチーブンス反応
m-chloroperbenzoic acid (mCPBA) メタクロロ過安息香酸
McLafferty rearrangement マクラファティ転位
McMurry reaction マクマリー反応
measurement 測定
median メジアン、中央値
medium 媒体、媒質
Meerwein arylation メーヤワインのアリール化反応
Meerwein-Ponndorf-Verley reduction メーヤワイン・ポンドルフ・バーレー還元
Meerwein's reagent メーヤワイン試薬 R3O+BF4-
Meisenheimer adduct マイゼンハイマー付加体
Meldrum's acid メルドラム酸
melting point 融点
MEM chloride
MeOCH2CH2OCH2Cl
membrane 膜
menthol メントール
mercaptan　 メルカプタン R-SH
mercaptoacetic acid メルカプト酢酸 HS-CH2CO2H
mercury 水銀 Hg
mercury acetate 酢酸水銀 Hg(OAc)2
Merrifield Solid-Phase Peptide Synthesis (SPPS) メリフィールドのペプチド固相合成法
meso compound　 メソ化合物
mesomeric effect メソメリー効果（共鳴効果）
mesomerism メソメリズム（共鳴）
mesyl chloride 塩化メシル CH3SO2-Cl (MsCl)
mesylate　 メシレート R-OMs
metabolism 代謝
metabolite 代謝物質、代謝中間体
metacyclophane メタシクロファン
metal exchange reactions 金属交換反応
metalation 金属化、メタル化
metal-carbene complexes 金属カルベン錯体
metallocenes メタロセン
metalloenzyme 金属酵素
metastable state 準安定状態
metathesis　 メタセシス
methacrolein メタクロレイン
methallyl alcohol メタリルアルコール
methanesulfonic acid メタンスルホン酸 CH3-SO3H
methanethiol メタンチオール CH3-SH
methanol メタノール CH3-OH
methanolic hydrogen chloride メタノール性塩酸 HCl/MeOH
methanolysis 加メタノール分解
methine　 メチン
methionine メチオニン
methoxyacetonitrile メトキシアセトニトリル MeOCH2CN
methyl acetoacetate アセト酢酸メチル MeCOCH2CO2Me
methyl acrylate アクリル酸メチル CH2=CHCO2Me
methyl iodide ヨウ化メチル CH3-I
methyl vinyl ketone メチルビニルケトン (MVK) MeCOCH=CH2
methylation メチル化
methylene メチレン
methylene chloride 塩化メチレン、ジクロロメタン CH2Cl2
methyllithium メチルリチウム CH3-Li
methylmagnesium bromide 臭化メチルマグネシウム MeMgBr
Meyer-Schuster rearrangement マイヤー・シュースター転位
micelle　 ミセル
Michael reaction マイケル反応
micro ミクロ
microbial metabolite 微生物代謝産物
microbial transformation 微生物変換
microsome ミクロソーム
migration 移動、渡り、マイグレーション
migratory aptitude 移動能
Mislow-Evans rearrangement Mislow-Evans 転位
Mitsunobu reaction　 光延反応
mixture 混合物
mobile phase (in chromatography) 移動層
moiety 半分ほど、一部分
molar absorption coefficient モル吸光係数
molar absorptivity モル吸光率
molarity モル濃度
mole モル
molecular formula 分子式
molecular ion 分子イオン
molecular mechanics calculation 分子力学計算
molecular modeling 分子モデリング（分子計算手法）
molecular orbital 分子軌道
molecular sieves 分子ふるい（篩）
molecular weight 分子量
molecule 分子
molozonide モロゾニド
molybdenum モリブデン Mo
molybdenum carbene complexes モリブデンカルベン錯体
momentum 運動量
monoclonal antibodies (MAbs) モノクローナル抗体
monolayer 単分子層
monomer モノマー、単量体
monosaccharides 単糖（類）
Montmorillonite モンモリロナイト（粘土の一種）
Morita-Baylis-Hillman reaction 森田・ベイリス・ヒルマン反応
morphine モルヒネ
morpholine モルホリン
mucochloric acid ムコクロル酸 OHC-CCl=CCl-CO2H
Mukaiyama aldol reaction 向山アルドール反応
multiple bond 多重結合
muscone ムスコン
mutagen （突然）変異原
mutagenesis 変異導入
mutation 突然変異
myristic acid ミリスチン酸
- N -
2-naphthol 2-ナフトール
N,N,N',N'-
tetramethylethylenediamine		 N,N,N',N'-テトラメチルエチレンジアミン
Nagata hydrocyanation 永田ヒドロシアノ化反応
naphthalene ナフタリン
naphthoquinone ナフトキノン
Nazarov cyclization ナザロフ環化
N-bromosuccinimide (NBS) N-ブロモスクシンイミド
n-butyllithium n-ブチルリチウム n-BuLi
N-chlorosuccinimide (NCS) N-クロロスクシンイミド
Neber rearrangement ネバー転位
Nef reaction ネフ反応
Negishi coupling 根岸カップリング
neighboring group participation 隣接基関与
Nenitzescu indole synthesis ネニチェスクのインドール合成法
neon　 ネオン Ne
neutron 中性子
Newman projection ニューマン投影法
Nicholas reaction ニコラス反応
nickel　 ニッケル Ni
nicotine ニコチン
ninhydrin　 ニンヒドリン
niobium ニオブ Nb
niobium chloride 塩化ニオブ
N-iodosuccinimide (NIS) N-ヨードスクシンイミド
nitration ニトロ化
nitrene ニトレン
nitric acid 硝酸 HNO3
nitrile　 ニトリル R-CN
nitrile oxide ニトリルオキシド
nitrilium ion ニトリリウムイオン
nitro compounds ニトロ化合物
nitroalkane ニトロアルカン R-NO2
nitrobenzene ニトロベンゼン PhNO2
nitrogen 窒素 N
nitromethane ニトロメタン CH3NO2
nitrone ニトロン
nitrophenol ニトロフェノール
nitrosamine ニトロソアミン RR'N-N=O
nitroso compounds ニトロソ化合物
nitrosyl chloride 塩化ニトロシル NOCl
nitrous oxide 亜酸化窒素、一酸化二窒素 N2O
nitryl chloride nitroyl chloride、塩化ニトロイル NO2Cl
N-methyl-2-pyrrolidone N-メチル-2-ピロリドン
N-methylmorpholine
N-oxide (NMO)		 N-メチルモルホリン-N-オキシド
NMR spectroscopy 核磁気共鳴スペクトロスコピー
noble gases 希ガス
NOESY 核オーバーハウザー効果相関分光法
nomenclature 専門語、術語、学名
nonclassical cations 非古典的カチオン
nonionic reactions 非イオン的反応
non-linear effect 非線形効果
norbornadiene ノルボルナジエン
norbornene ノルボルネン
norephedrine ノルエフェドリン
Noyori hydrogenation 野依水素化（野依還元）
Nozaki-Hiyama-Kishi coupling 野崎・檜山・岸カップリング（NHK 反応）
nuclear magnetic resonance spectroscopy
(NMR spectroscopy)		 核磁気共鳴
nuclear spin 核スピン
nucleic acids 核酸
nucleophile 求核剤
nucleophilic substitution 求核置換
nucleophilicity 求核性
nucleosides ヌクレオシド
nucleotides ヌクレオチド
nucleus 核
- O -
octanol オクタノール
octyne オクチン
olefin オレフィン
olefin metathesis オレフィンメタセシス
oleic acid オレイン酸
oligomer オリゴマー
oligomeric オリゴマーの
oligomerization オリゴマー化
oligonucleotides オリゴヌクレオチド
oligopeptides オリゴペプチド
oligosaccharides オリゴ糖
o-nitrobenzenesulfonyl chloride o-ニトロベンゼンスルホニルクロリド 2-NO2C6H4SO2Cl
Oppenauer oxidation オッペナウアー酸化
optical activity 光学活性
optical antipodes 光学対掌体、光学鏡像体
optical purity 光学純度
optical resolution 光学分割
optical rotation 旋光
optical yield 光学収率
optically pure 光学的に純粋
orbital 軌道
orbital coefficients 軌道係数
orbital symmetry 軌道対称性
organoaluminium reagents 有機アルミニウム試薬
organocopper reagent 有機銅試薬
organolithium reagent 有機リチウム試薬
organometallic reagents 有機金属試薬
organotin 有機スズ
ortho ester オルトエステル
osmium オスミウム Os
osmium tetroxide 四酸化オスミウム OsO4
osmotic pressure 浸透圧
oxalic acid シュウ酸
oxalyl chloride 塩化オキサリル
oxaziridine オキサジリジン
oxazole オキサゾール
oxazolidinone　 オキサゾリジノン
oxazoline オキサゾリン
oxetane オキセタン
oxidant 酸化剤
oxidation 酸化
oxidative addition 酸化的付加
oxidative coupling 酸化的カップリング
oxide 酸化物
oxidize 酸化する
oxidizing agents 酸化剤
oxime オキシム
oxirane オキシラン
Oxone® オキソン
oxonium ions オキソニウムイオン
oxy-Cope rearrangement オキシコープ転位
oxygen 酸素 O
oxymercuration オキシ水銀化
ozone オゾン O3
ozonide オゾニド
ozonolysis オゾン分解
- P -
Paal-Knorr pyrrole synthesis パール・クノール ピロール合成法
p-acetamidobenzenesulfonyl azide パラアセトアミドベンゼンスルフォニルアジド p-AcNHC6H4SO2N3
palladacycles パラダサイクル
palladium パラジウム Pd
palladium acetate 酢酸パラジウム Pd(OAc)2
palladium acetylacetonate ビス(アセチルアセトナト)パラジウム(II)
palladium on carbon パラジウム-炭（パラ炭） Pd/C
palladium on charcoal パラジウム-炭（パラ炭） Pd/C
paracyclophane パラシクロファン
paraffin パラフィン
paramagnetic 常磁性
parameter パラメーター
parent ion (in mass spectrometry) 親イオン
partition coefficient 分配係数
Passerini reaction パセリニ反応
Paterno-Büchi reaction パテルノ・ビューキ反応
pattern recognition パターン認識
Pauson-Khand reaction ポーソン・カンド反応
Payne Rearrangement ペイン転位
penem ペネム
penicillin ペニシリン
peptides ペプチド
peptidoglycan ペプチドグリカン
peracid 過酸 例：R-CO3H
perchloric acid 過塩素酸 HClO4
pericyclic reaction ペリ環状反応
periodic acid 過ヨウ素酸 HIO4
periodic table 周期表
periplanar　 ペリプラナー
Perkin Reaction パーキン反応
peroxidase ペルオキシダーゼ
peroxides 過酸化物
perspective formula 透視式
pesticide 農薬
Petasis Reaction ペタシス反応
Peterson olefination ピーターソンオレフィン合成
petroleum 石油
Pfitzner-Moffatt oxidation ピッツナー・モファット酸化
pH 水素イオン指数
pharmacokinetics 薬物動態学
phase transfer catalyst 相関移動触媒
phenacyl bromide 臭化フェナシル PhCOCH2Br
phenanthrene フェナントレン
phenol フェノール（石炭酸） PhOH
phenonium ion フェノニウムイオン
phenoxyacetic acid フェノキシ酢酸 PhOCH2CO2H
phenyl acetate 酢酸フェニル PhOAc
phenyl chloroformate クロロギ酸フェニル ClCO2Ph
phenyl group フェニル基 -Ph, -C6H5
phenyl isocyanate イソシアン酸フェニル PhN=C=O
phenyl isothiocyanate イソチオシアン酸フェニル PhN=C=S
phenylalanine フェニルアラニン
phenylglycine フェニルグリシン
phenylhydrazine フェニルヒドラジン PhNHNH2
phenylhydrazone フェニルヒドラゾン PhNHN=CRR'
phenyllithium フェニルリチウム PhLi
phenylmagnesium bromide 臭化フェニルマグネシウム PhMgBr
pheromone フェロモン（誘引物質）
phosgene　 ホスゲン COCl2
phosphazene フォスファゼン
phosphine ホスフィン
phospholipid リン脂質
phosphoramide ホスホルアミド
phosphorane ホスホラン
phosphorescence 燐光
phosphoric acid リン酸 H3PO4
phosphorus リン（燐） P
phosphorus oxychloride オキシ塩化リン POCl3
phosphorus tribromide 三臭化リン PBr3
phosphorus ylide リンイリド R3P=CR'R"
phosphoryl chloride 塩化ホスホリル POCl3
phosphorylation ホスホリル化
photoaffinity labelling 光親和性ラベル化
photochemical reaction 光化学的反応（光反応）
photochemistry 光化学
photochromism ホトクロミズム
photogalvanic cell 光化学電池
photoimaging ホトイメージング
photolysis 光分解
photon 光子
photooxidation 光酸化
photooxygenation 光酸素化
photosensitizer 光増感剤
photosynthesis 光合成
photovoltaic cell 光電池
phthalic acid フタル酸
phthalic anhydride 無水フタル酸
phthalide フタリド
phthalimide フタルイミド
physical properties 物理的性質
picrate ピクレート（ピクリン酸塩）
picric acid ピクリン酸
Pictet-Spengler isoquinoline synthesis　　 ピクテ・スペングラー反応
pinacol ピナコール
pinacol rearrangement ピナコール転位
pinacolborane ピナコールボラン
Pinner reaction ピンナー反応
piperazine ピペラジン
piperidine ピペリジン
pivaldehyde ピバルアルデヒド
pivalic acid ピバル酸
pivaloyl chloride 塩化ピバロイル
pKa pKa（電離指数）
planar　 平面の、面性
planar chirality 面性キラリティー
platinum プラチナ（白金） Pt
plutonium プルトニウム Pu
polar aprotic solvent 極性非プロトン性溶媒
polar reactions 極性反応
polar solvent　 極性溶媒
polarimeter 旋光計
polarity 極性
polarizability 分極率
polarization 分極
polarography ポーラログラフィー
Polonovski reaction ポロノフスキー反応
polycyclic system 多環式（化合物）
polyether ポリエーテル
polyethylene glycol ポリエチレングリコール
polyfunctional 多官能性
polyketides ポリケチド（ポリケタイド）
polymer ポリマー
polymerase chain reaction (PCR) ポリメラーゼ連鎖反応
polymeric ポリマーの
polymerization 重合
polymethylhydrosiloxane ポリメチルヒドロシロキサン
polypeptides ポリペプチド
polyquinanes ポリキナン
polysaccharides 多糖（類）
Pomeranz-Fritsch reaction ポメランツ・フリッシュ反応
porphyrins ポルフィリン
potassium カリウム K
potassium carbonate 炭酸カリウム K2CO3
potassium ferricyanide フェリシアン化カリウム K3[Fe(CN)6]
potassium ferricyanate フェロシアン化カリウム K4[Fe(CN)6]3
potassium hydride 水素化カリウム KH
potassium hydroxide 水酸化カリウム KOH
potassium permanganate 過マンガン酸カリウム KMnO4
potassium superoxide 超酸化カリウム KO2-
potassium t-butoxide　 カリウムt-ブトキシド t-BuOK
potent　 強力な
potential energy ポテンシャルエネルギー
praseodymium プラセオジム Pr
precipitation 沈殿
precision 精確、精密
precursor　 前駆体
pressure 圧力
primary kinetic isotope effect 一次速度論的同位体効果
principle of microscopic reversibility 微視的可逆性の原理
Prins reaction プリンス反応
priority 優先権、優先順位
probability 確率
probe プローブ、探り針
process 経過、プロセス
prochiral プロキラル
prochiral center プロキラル中心
product development control プロダクトデベロップメントコントロール
progesterone プロゲステロン
proline プロリン
prolinol プロリノール
propagation 繁殖
propanol プロパノール
propargyl alcohol プロパルギルアルコール HC≡CCH2OH
propellanes プロペラン
propene プロペン CH2=CHCH3
properties 特質、特性
propiolic acid プロピオール酸 HC≡CCO2H
propionic acid プロピオン酸 CH3CH2CO2H
propionitrile プロピオニトリル CH3CH2CN
propylene oxide プロピレンオキシド
prostaglandins プロスタグランジン
prostanoids プロスタノイド
proteases プロテアーゼ（タンパク質分解酵素）
protective group 保護基
protein kinase C (PKC) プロテインキナーゼＣ
proteins タンパク質
proteoglycan プロテオグリカン
protic solvents プロトン性溶媒
proton プロトン H+
pseudo-axial　 擬アキシャル
pseudoephedrine シュードエフェドリン
pseudo-equatorial 擬エカトリアル
pseudorotation 擬似回転
p-toluenesulfonic acid p-トルエンスルホン酸 p-MeC6H4SO3H
p-toluenesulfonyl chloride p-トルエンスルホニルクロリド p-MeC6H4SO2Cl
p-toluenesulfonylhydrazide p-トルエンスルホニルヒドラジド p-MeC6H4SO2NHNH2
Pummerer reaction プンメラー転位
purify 精製する
purine プリン
purine bases プリン塩基
purity　 純度
pyramidal inversion ピラミッド反転
pyranoses ピラノース
pyrazole ピラゾール
pyrene　 ピレン
pyrethrin ピレスリン
pyridine ピリジン
pyridinium chlorochromate (PCC) クロロクロム酸ピリジニウム (C5H5N+H)・ClCrO3-
pyridinium dichromate (PDC) 二クロム酸ピリジニウム (C5H5N+H)2・Cr2O72-
pyridinium p-toluenesulfonate (PPTS) ピリジニウムp-トルエンスルホネート
pyridone ピリドン
pyrimidine ピリミジン
pyroglutamic acid ピログルタミン酸
pyrolysis 熱分解
pyrrole　 ピロール
pyrrolidine　 ピロリジン
pyruvic acid ピルビン酸
- Q -
quadrupole mass analyser 四重極質量分析計
qualitative analysis 定性分析
quantitative analysis 　 定量分析
quantum mechanics 量子力学
quantum yield 量子収率
quasi-axial 擬アキシャル
quaternary carbon 四級炭素
quenching 消光、焼入れ
quinine 　 キニーネ
quinoline　 キノリン
quinomethane キノメタン
quinone　 キノン
quinone methide　 キノンメチド
quinuclidine キヌクリジン
- R -
racemate ラセミ体
racemic 　 ラセミの
racemization ラセミ化
radiation chemistry 　 放射化学
radical addition ラジカル付加
radical anion ラジカルアニオン
radical cation ラジカルカチオン
radical chain reaction ラジカル連鎖反応
radical cyclization ラジカル環化
radical initiator ラジカル開始剤
radical quenching agent ラジカル消去剤（ラジカルクエンチャー）
radioactive 　 放射性の
radioisotope 放射性同位元素
radium ラジウム Ra
radon ラドン Rn
Ramberg-Bäcklund reaction ランベルグ・ベックルント反応
Raney nickel　 ラネーニッケル
rate constant 速度定数
rate equation 反応速度式
rate-determining step 律速段階
ratio 　 比、レシオ
reactant 反応物
reaction mechanism 反応機構
reaction path 反応経路
reaction pathway 反応経路
reaction profiles　 反応プロフィール
reactive intermediate 反応性中間体
reagent 試薬
rearrangement 転位（反応）
recovery 回収
recrystallization 再結晶化
redox potential　 酸化還元電位
reducing agent 還元剤
reduction 還元
reductive amination 還元的アミノ化
reductive elimination 還元的脱離
re-face re-面
reference electrode 参照電極
reflux 還流
Reformatsky reaction レフォルマツキー反応
refractive index 屈折率
regioselectivity 位置選択性
Reimer-Tiemann reaction ライマー・ティーマン反応
Reissert reaction ライサート反応
relaxation time 緩和時間
replication 複製
report 報告
representative sample 代表的なサンプル
reproducibility 再現性
repulsion 反発
requisite　 必要な
reserpine レゼルピン
resolution 分解能
resonance 共鳴
resonance effect 共鳴効果
restricted rotation 束縛（を受けた）回転
retention of configuration 立体配置の保持
retinoids レチノイド
retro-aldol reaction 逆アルドール反応
retro-ene reaction 逆エン反応
retrosynthetic analysis 逆合成解析
reversed-phase chromatography 逆層クロマトグラフィー
reversible reaction 可逆反応
revolutions per minute (rpm) 回転数／分
rhenium レニウム Re
rhodamine dyes ローダミン染料
rhodium ロジウム Rh
rhodium acetate 酢酸ロジウム Rh2(OAc)4
ribonuclease　 リボヌクレアーゼ（RNA分解酵素）
ribonucleic acids (RNA) リボ核酸
ribonucleotides リボヌクレオチド
ribosomes リボソーム
ring closing metathesis 閉環メタセシス反応
ring strain 環歪み
Ritter reaction リッター反応
Robinson annulation reaction ロビンソン環化反応
Robinson-Schöpf reaction ロビンソン・ショップ反応
Rochelle salt ロシェル塩
Rosenmund reduction ローゼンムント還元
rotamer 回転異性体
rotational barrier 回転障壁
rotaxanes ロタキサン
rubber ゴム
rubidium ルビジウム Rb
Rubottom oxidation ルボトム酸化
ruthenium　 ルテニウム Ru
ruthenium tetroxide 四酸化ルテニウム RuO4
- S -
saccharides 糖類
saccharin サッカリン
salcomine サルコミン
salen サレン
salicyl alcohol サルチルアルコール
salt 塩
salting out 塩析
samarium サマリウム Sm
Sandmeyer reaction ザンドマイヤー反応
Sanger's reagent サンガー試薬
saturated 飽和の
saturation 飽和
Saytzeff rule セイチェフ則（ザイツェフ則）
scandium スカンジウム Sc
scavenger スカベンジャー
Schiff's bases シッフ塩基 RCH=NR'
Schmidt reaction シュミット反応
Schotten-Baumann reaction ショッテン・バウマン反応
Schwartz reagent シュワルツ試薬 Cp2Zr(H)Cl
scintillation counter シンチレーション計数管
scrambling スクランブリング（ごちゃまぜにする）
secondary carbon 二級炭素
secondary isotope effect 二次同位体効果
selective cleavage 選択的解裂
selenenic acid セレネン酸 R-SeOH
selenide セレナイド（セレニド） R-Se-R'
seleninic acids セレニン酸 R-SeO2H
selenium セレン Se
selenium dioxide 二酸化セレン SeO2
semicarbazide セミカルバジド
semicarbazone セミカルバゾン
semiempirical calculations 半経験的（分子軌道）計算
semisynthetic　 半合成的
separable 分離可能な
Sephadex セファデックス
serine セリン
sesquiterpenoids セスキテルペノイド
Shapiro reaction シャピロ反応
Sharpless aminohydroxylation シャープレスアミノヒドロキシル化反応
Sharpless dihydroxylation シャープレスジヒドロキシル化反応
Sharpless epoxidation シャープレスエポキシ化反応
shielding effect 遮蔽効果
si-face　 si 面
sigmatropic rearrangement シグマトロピー反応
silanes　 シラン
silanols シラノール R3SiOH
silica gel シリカゲル
silicon シリコン、ケイ素 Si
siloxanes シロキサン
silver 銀 Ag
silyl enol ether　 シリルエノールエーテル
silyl ether シリルエーテル R'O-SiR3
silyl group シリル基
Simmons-Smith reaction シモンズ・スミス反応
simultaneous reactions 同時反応
single electron transfer (SET) 単電子移動
singlet oxygen 一重項酸素 1O2
six-membered ring 六員環
skeleton 骨格
skew スキュー（配座）
Skraup reaction スクラウプキノリン合成法
Smiles rearrangement スマイルズ転位
SN2 mechanism SN2機構
sodium ナトリウム Na
sodium acetate 酢酸ソーダ AcONa
sodium acetylide ナトリウムアセチリド HC≡CNa
sodium alkoxide ナトリウムアルコキシド R-ONa
sodium amalgam ナトリウムアマルガム Na-Hg
sodium amide ナトリウムアミド NaNH2
sodium azide アジ化ナトリウム NaN3
sodium bicarbonate 炭酸水素ナトリウム（重曹） NaHCO3
sodium borohydride ホウ水素化ナトリウム（テトラヒドロホウ酸ナトリウム） NaBH4
sodium carbonate 炭酸ナトリウム（炭酸ソーダ） Na2CO3
sodium chlorate 塩素酸ナトリウム NaClO3
sodium chloride 塩化ナトリウム（食塩） NaCl
sodium chlorite 亜塩素酸ナトリウム NaClO2
sodium cyanate シアン酸ナトリウム NaOCN
sodium cyanide シアン化ナトリウム NaCN
sodium cyanoborohydride シアノトリヒドロホウ素ナトリウム NaBH3CN
sodium hexamethyldisilazide
sodium hydride 水素化ナトリウム NaH
sodium hydroxide 水酸化ナトリウム NaOH
sodium iodide ヨウ化ナトリウム NaI
sodium methoxide ナトリウムメトキサイド MeONa
sodium nitrate 硝酸ナトリウム NaNO3
sodium nitrite 亜硝酸ナトリウム NaNO2
sodium periodate 過ヨウ素酸ナトリウム NaIO4
sodium triacetoxyborohydride
NaB(OAc)3H
solubility 溶解性（溶解度）
solute 溶質
solution 溶液
solvation 溶媒和
solvent 溶媒
solvent front (in chromatography) ソルベントフロント
solvolysis 加溶媒分解
Sommelet reaction ソムレー反応
Sommelet rearrangement ソムレー転位
sonication 超音波処理
Sonogashira coupling 薗頭カップリング
sorbic acid ソルビン酸
sparteine スパルテイン
species 種
specific gravity 比重
specific rotation 比旋光度
spectrometer　 分光計
spectrometry　 分析法（質量、Ｘ線などの）
spectroscopy 分光学
sphingolipid スフィンゴ脂質
spin decoupling スピンデカップリング
spin multiplicity スピン多重度
spin-spin coupling スピン-スピンカップリング
squaric acid スクエア酸
staggered staggered conformation: ねじれ型配座
stannane　 スタナン
stannoxanes スタノキサン
starch デンプン
starting material 出発物
statistical factor 統計的要素
Staudinger reaction シュタウジンガー反応
Steglich esterification シュテグリッヒエステル化反応
stereocontrolled total synthesis 立体選択的全合成
stereoelectronic effect 立体電子効果
stereogenic center 立体中心
stereoisomerism 立体異性
stereoisomers 立体異性体
stereoselective synthesis 立体選択的合成
stereoselectivity 立体選択性
stereospecificity 立体特異性
steric crowding 立体障害（立体密集？）
steric effects 立体効果
steric environment 立体環境
steric factor 立体要因
steric hindrance 立体障害
sterically hindered 立体障害された
steroids ステロイド
Stetter reaction ステッター反応
Stevens rearrangement スティーブンス転位
Stille coupling　 スティレカップリング
Stobbe condensation ストッベ縮合
stoichiometric　 化学量論的な
stoichiometry　 化学量論
Stork enamine synthesis ストークエナミン合成法
strain 歪み
Strecker synthesis ストレッカー合成
strontium ストロンチウム Sr
structural formula 構造式
structure-activity relationship (SAR) 構造活性相関
styrene スチレン PhCH=CH2
substituent　 置換基
substitution 置換
substrate 基質
succinic acid コハク酸
succinic anhydride コハク酸無水物（無水コハク酸）
suicide inhibition 自殺的（酵素）阻害
sulfamic acid スルファミン酸 NH2SO3H
sulfenic acid スルフェン酸 R-SOH
sulfenyl group スルフェニル基 -SOH
sulfide　 スルフィド（サルファイド） R-S-R'
sulfinic acid スルフィン酸 R-SO2H
sulfonamides スルホンアミド R-SO2NR'R"
sulfonate スルホン酸塩 R-SO3-
sulfonation スルホニル化
sulfone　 スルホン R-SO2-R'
sulfonic acids スルホン酸 R-SO3H
sulfonimides スルホアミド R-SO2NR'R"
sulfonium salts スルホニウム塩 R3S+X-
sulfoxide スルホキシド R-SO-R'
sulfur 硫黄 S
sulfur dioxide 二酸化硫黄 SO2
sulfur trioxide 三酸化硫黄 SO3
sulfur ylide 硫黄イリド R2S+-C-R'R"
sulfuric acid 　 硫酸 H2SO4
sultam スルタム
Super Hydride スーパーハイドライド LiBEt3H
supercritical fluid 超臨界流体
supersaturation 過飽和
suprafacial スープラフェイシャル
supramolecular 超分子の
surface 表面
surfactant 界面活性剤
suspension 懸濁
Suzuki-Miyaura coupling 鈴木・宮浦カップリング
Swern oxidation スワーン酸化
symmetry 対称
syn syn
syn-elimination syn-脱離
synthesis 合成
synthon シントン
- T -
Tamao-Fleming oxidation 玉尾・フレミング酸化
tantalum タンタル Ta
tartaric acid 酒石酸
tautomerism 互変異性
tautomerization 互変異性化
TBAF テトラブチルアンモニウムフロリド n-Bu4NF
Tebbe reagent　 Tebbe 試薬
technetium テクネチウム Tc
telluride テルル化物
tellurium テルル Te
terpene テルペン
terpenoid テルペノイド
tertiary carbon （第）三級炭素
testosterone　 テストステロン
tether つなぎなわ（牛・馬の）
tetrabutylammonium bromide 臭化 テトラブチルアンモニウム n-Bu4NBr
tetracyclines テトラサイクリン
tetrahedral intermediate　 四面体型中間体
tetrahydrofuran (THF) テトラヒドロフラン
tetrakis(triphenylphosphine)-
palladium(0)		 テトラキス(トリフェニルホスフィン)パラジウム Pd(PPh3)4
tetrapropylammonium perruthenate 過ルテニウム酸テトラプロピルアンモニウム (C3H7)4N+ RuO4−
TFA トリフロロ酢酸 CF3CO2H
thallium タリウム Tl
thermodynamic control 熱力学的コントロール
thermodynamics 熱力学
thermolysis 熱分解
thesis (複数形 theses) 学位論文
thexylborane テキシルボラン
thiamine チアミン
thiazolium チアゾリウム（塩）
thin-layer chromatography (TLC) 薄層クロマト
thioacetal チオアセタール
thioanisole チオアニソール PhSMe
thiocarbonyldiimidazole (TCDI)　 1,1'-チオカルボニルジイミダゾール
thiocarboxylic acids チオカルボン酸 RCOSH
thiocyanate チオシアネート -SCN
thioether チオエーテル R-S-R'
thiohemiacetal チオヘミアセタール
thioketone チオケトン RR'C=S
thiolactam チオラクタム
thiols チオール（メルカプタン） R-SH
thionyl chloride 塩化チオニル SOCl2
thiophene チオフェン
thiophenol チオフェノール PhSH
thiourea チオ尿素
Thorpe-Ingold effect ソープ-インゴールド効果
threo トレオ（スレオ）
threonine スレオニン（トレオニン）
through-space electron transfer スルースペース電子移動
thymine チミン
Tiffeneau-Demjanov rearrangement ティフノー・デミヤノフ転位
tight ion pair 強固なイオン対
tiglic acid チグリン酸
time-of-flight mass spectrometer 飛行時間型質量分析計
tin スズ（錫） Sn
Tishchenko reaction ティシュチェンコ反応
titanium チタン Ti
titanium tetrachloride 四塩化チタン TiCl4
titanium tetraisopropoxide テトライソプロポキシチタン Ti(Oi-Pr)4
titanocene dichloride ジクロロチタノセン Cp2TiCl2
titration 滴定
TMEDA N,N,N',N'-テトラメチルエチレンジアミン
Tollens reagent トレンス試薬 aq. NH3 + AgNO3
toluene　 トルエン PhMe
torquoselectivity トルク選択性
torsion angle ねじれ角
torsional strain 重なりひずみ（ねじれひずみ）
tosylate トシレート
total synthesis 全合成
toxicity 毒性
toxicology 毒物学
toxin 毒素
trace element 微量元素
trajectory 弾道、軌道
transannular reaction 渡環反応（トランスアニュラー反応）
transformation 変換
transient species 過渡的な種
transition metal 遷移金属
transition state 遷移状態
transition state analogue 遷移状態アナログ
transmetallation 金属交換反応（トランスメタル化）
transoid conformation トランソイド配座
tributylphosphine トリブチルホスフィン n-Bu3P
tributyltin hydride 水素化トリブチルスズ n-Bu3SnH
triethylamine トリエチルアミン Et3N
triethylborane トリエチルボラン Et3B
triflate トリフレート -OSO2CF3
triflic anhydride トリフロロメタンスルホン酸無水物 (CF3SO2)2O
trifluoroacetic acid トリフロロ酢酸 CF3CO2H
trifluoroacetic anhydride 無水トリフロロ酢酸 (CF3CO)2O
trifluoromethanesulfonic acid トリフロロメタンスルホン酸 CF3SO3H
triglyceride トリグリセリド
trimer 三量体
trimethyl orthoformate オルトギ酸メチル HC(OMe)3
trimethylaluminium トリメチルアルミニウム AlMe3
trimethylenemethane トリメチレンメタン
trimethyloxonium tetrafluoroborate Meerwein試薬 Me3O+BF4-
trimethylsilyl azide アジ化トリメチルシリル Me3SiN3
trimethylsilyl trifluoromethanesulfonate トリメチルシリルトリフレート Me3SiOTf
trimethylsilylacetylene トリメチルシリルアセチレン HC≡CSiMe3
triphenylphosphine トリフェニルホスフィン Ph3P
triplet state 三重項
tritium トリチウム T, 3H
trityl ether トリチルエーテル R-O-CPh3
trivial name 慣用名
tropolones トロポロン
tropone トロポン
tropylium ion トロピリウムイオン
tryptophan トリプトファン
Tsuji-Trost reaction 辻-トロスト反応
tungsten タングステン W
turnover frequency (in catalysis) ターンオーバー・フリークエンシー
two-dimensional chromatography 二次元クロマトグラフィー
tyrosine チロシン
- U -
Ugi reaction (four component condensation , 4CC) 　 Ugi反応（４成分連結反応）
Ullmann reaction ウルマン反応
ultrasound 超音波
ultraviolet-visible spectroscopy (UV-Vis spectroscopy) 紫外-可視分光法
umpolung ウムポールンク（極性転換）、reverse polarization
unimolecular unimolecular reaction（単分子反応）
unsaturated acid 不飽和酸
uranium ウラニウム U
urea 尿素 (NH2)2C=O
urethane ウレタン ROCONR'R"
- V -
vacuum 真空
vacuum distillation 減圧蒸留（真空蒸留）
valence 原子価
valence isomerism 原子価異性
valine　 バリン
van der Waals forces ファン・デル・ワール ス力
van der Waals interaction ファン・デル・ワール ス相互作用
vanadium バナジウム V
vanadyl acetylacetonate バナジルアセチルアセトネート VO(acac)2
vanillin　 バニリン
variant 変形、別形
vial バイアル、ガラス瓶
vicinal ビシナル
Vilsmeier reagent フィルスマイヤー試薬、ビルスマイヤー試薬
Vilsmeier-Haack reaction フィルスマイヤー・ハーク反応、ビルスマイヤー・ハーク反応
vinyl acetate　 酢酸ビニル CH2=CHOAc
vinyl bromide 臭化ビニル CH2=CHBr
vinyl group ビニル基
vinyllithium　 ビニルリチウム CH2=CHLi
vinylmagnesium bromide 臭化ビニルマグネシウム CH2=CHMgBr
vinylogous amide ビニロガスアミド
vinylogous ester ビニロガスエステル
viscosity 粘性、粘度
vitamin C ビタミンＣ
von Braun cyanogen bromide reaction フォンブラウン反応
von Richter reaction フォンリヒター反応
- W -
Wacker reaction ワッカー反応（酸化）
Wagner-Meerwein rearrangement Wagner-Meerwein 転位
Walden inversion ワルデン反転
water 水 H2O
wavelength 波長
wavenumber 波数
Weinreb ketone synthesis ワインレブのケトン合成法
Weiss reaction ワイス反応
Wharton reaction ウォートン反応
Wilkinson's catalyst ウィルキンソン触媒 RhCl(PPh3)3
Williamson ether synthesis ウィリアムソンのエーテル合成法
Wittig reaction　 ウィッティッヒ反応、ヴィティッヒ反応
Wolff rearrangement ウォルフ転位
Wolff-Kishner reduction ウォルフ・キシュナー還元（ヴォルフ...）
Woodward cis-hydroxylation ウッドワードシス水酸基化反応
Woodward-Hoffmann rules ウッドワード・ホフマン則
workup 後処理
- X -
xanthate　 キサントゲン酸塩 RO(C=S)S-
xenon キセノン Xe
xenon lamp キセノンランプ
xylene キシレン
- Y -
Yamaguchi esterification 山口エステル化法
ylide イリド
ynamine　 イナミン
ynol　 イノール
ytterbium イッテルビウム Yb
yttrium イットリウム Y
- Z -
zeolite ゼオライト（沸石）
Ziegler-Natta catalyst Ziegler-Natta 触媒
zinc 亜鉛 Zn
zinc-copper couple 亜鉛ー銅合金 Zn-Cu
zirconium ジルコニウム Zr
zirconocene dichloride 二塩化ジルコノセン
zwitterions 両性イオン（双性イオン）
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Acetoacetic Ester Synthesis

Acyloin Condensation

Alder-Ene Reaction

Aldol Reaction

Amadori Rearrangement

Arbuzov Reaction

Arndt-Eistert Synthesis

Baeyer-Villiger Oxidation

Bamberger Rearrangement

Bamford-Stevens Reaction

Barbier Reaction

Barbier-Wieland Degradation

Barton Reaction

Barton-McCombie Reaction

Beckmann Rearrangement

Benzilic Acid Rearrangement

Benzoin Condensation

Bergman Reaction

Biginelli Reaction

Birch Reduction

Bischler-Napieralski Reaction

Bouveault-Blanc Reduction

Brook Rearrangement

Bucherer Reaction 　

Buchwald-Hartwig Aryl Amination

Cannizzaro Reaction

Carroll Rearrangement

Castro-Stephens Coupling

Chichibabin Reaction

Chugaev Reaction

Claisen Condensation

Claisen Rearrangement

Claisen-Schmidt Condensation

Clemmensen Reaction

Cope Elimination

Cope Rearrangement

Corey-Bakshi-Shibata Reduction (CBS)

Corey-Fuchs Reaction

Corey-Kim Oxidation

Corey-Winter Olefin Synthesis

Cornforth Rearrangement

Criegee Reaction

Curtius Rearrangement

Dakin Reaction

Darzens Condensation

de Mayo Reaction

Delepine Reactions

Demjanov Rearrangement

Dess-Martin Oxidation

Dieckmann Condensation

Diels-Alder Reaction

Dienone-Phenol Rearrangement

Dimroth Rearrangement

Directed ortho Metalation

Duff Reaction

Edman Degradation

Erlenmeyer-Plochl Azlactone and Amino Acid Synthesis

Eschenmoser Fragmentation

Eschweiler-Clarke Reaction

Favorskii Rearrangement

Finkelstein Reaction

Fischer Esterification

Fischer Indole Synthesis

Friedel-Crafts Reaction

Friedlander Synthesis

Fries Rearrangement

Gabriel Synthesis

Gattermann-Koch Reaction　

Grignard Reaction

Grob Fragmentation

Hantzsch Pyridine Synthesis

Heck Reaction (Mizoroki-Heck Reaction)

Hell-Volhard-Zelinsky Reaction

Henry Reaction

Hofmann Elimination

Hofmann Reaction

Hofmann-Loffler-Freytag Reaction

Horner-Wadsworth-Emmons Reaction

Hosomi-Sakurai Reaction

Huisgen Cycloaddition

Hunsdiecker Reaction

Hydroboration

Ireland-Claisen Rearrangement

Ito-Saegusa Oxidation

Japp-Klingemann Reaction　

Jones Oxidation

Julia Olefination

Julia-Kocienski Olefination

Knoevenagel Condensation　(又は）　

Knorr Quinoline Synthesis　（又は）　

Kochi Reaction 　

Kolbe Electrolytic Synthesis

Kolbe-Schmitt Reaction

Krapcho Decarbaloxylation

Kumada Coupling

Lawesson's Reagent

Lossen Rearrangement

Luche Reduction

Malonic Ester Synthesis

Mannich Reaction

McFadyen-Stevens Reaction

McMurry Reaction

Meerwein Arylation

Meerwein-Ponndorf-Verley Reduction

Merrifield Solid-Phase Peptide Synthesis (SPPS)

Meyer-Schuster Rearrangement

Michael Reaction

Mislow-Evans Rearrangement

Mitsunobu Reaction

Morita-Baylis-Hillman Reaction

Mukaiyama Aldol Reaction　

Nagata Hydrocyanation

Nazarov Cyclization

Neber Rearrangement

Nef Reaction

Negishi Coupling

Nenitzescu Indole Synthesis

Nicholas Reaction

Noyori Hydrogenation

Nozaki-Hiyama-Kishi Coupling

Olefin Metathesis

Oppenauer Oxidation

Oxy-Cope Rearrangement

Ozonolysis

Paal-Knorr Pyrrole Synthesis

Passerini Reaction

Paterno-Büchi Reaction

Pauson-Khand Reaction

Payne Rearrangement

Perkin Reaction

Petasis Reaction

Peterson Olefination

Pfitzner-Moffatt Oxidation

Pictet-Spengler Isoquinoline Synthesis

Pinacol Coupling Reaction

Pinacol Rearrangement

Pinner Reaction

Polonovski Reaction

Pomeranz-Fritsch Reaction (Schlittler-Muller Modification)

Prins Reaction

Pummerer Reaction

Ramberg-Bäcklund Reaction

Reformatsky Reaction

Reimer-Tiemann Reaction

Reissert Reaction

Ring Closing Metathesis

Ritter Reaction

Robinson Annulation Reaction

Robinson-Schöpf Reaction

Rosenmund Reduction　

Rubottom Oxidation

Sandmeyer Reaction

Schmidt Reaction

Schotten-Baumann Reaction

Shapiro Reaction

Sharpless Aminohydroxylation

Sharpless Dihydroxylation

Sharpless Epoxidation

Simmons-Smith Reaction

Skraup Reaction

Smiles Rearrangement

Sommelet Reaction

Sommelet Rearrangement

Sonogashira Coupling

Staudinger Reaction

Steglich Esterification

Stetter Reaction

Stevens Rearrangement

Stille Coupling

Stobbe Condensation 　

Stork Enamine Synthesis

Strecker Synthesis

Suzuki-Miyaura Coupling

Swern Oxidation

Tamao-Fleming Oxidation

Tebbe Olefination

Tiffeneau Reaction

Tishchenko Reaction

Tsuji-Trost Reaction

Ugi Reaction (Four component condensation , 4CC)

Ullmann Reaction

Vilsmeier-Haack Reaction

von Braun Cyanogen Bromide Reaction　

von Richter Reaction　

Wacker Reaction

Wagner-Meerwein Rearrangement

Walden Inversion

Weinreb Ketone Synthesis

Weiss Reaction

Wharton Reaction

Williamson Synthesis

Wittig Reaction　

Wolff Rearrangement

Wolff-Kishner Reduction

Woodward cis-Hydroxylation

Yamaguchi Esterification

周期律表


1 18
1
H
2
13
14
15
16
17		 2
He
3
Li		 4
Be		 5
B		 6
C		 7
N		 8
O		 9
F		 10
Ne
11
Na		 12
Mg		 3 4 5 6 7 8 9 10 11 12 13
Al		 14
Si		 15
P		 16
S		 17
Cl		 18
Ar
19
K		 20
Ca		 21
Sc		 22
Ti		 23
V		 24
Cr		 25
Mn		 26
Fe		 27
Co		 28
Ni		 29
Cu		 30
Zn		 31
Ga		 32
Ge		 33
As		 34
Se		 35
Br		 36
Kr
37
Rb		 38
Sr		 39
Y		 40
Zr		 41
Nb		 42
Mo		 43
Tc		 44
Ru		 45
Rh		 46
Pd		 47
Ag		 48
Cd		 49
In		 50
Sn		 51
Sb		 52
Te		 53
I		 54
Xe
55
Cs		 56
Ba		 *1 72
Hf		 73
Ta		 74
W		 75
Re		 76
Os		 77
Ir		 78
Pt		 79
Au		 80
Hg		 81
Tl		 82
Pb		 83
Bi		 84
Po		 85
At		 86
Rn
87
Fr		 88
Ra		 *2 104
Rf		 105
Db		 106
Sg		 107
Bh		 108
Hs		 109
Mt		 110
Ds		 111
Rg		 112
Uub		 113
Uut		 114
Uuq		 115
Uup		 116
Uuh		 117
Uus		 118
Uuo

*1 ランタノイド 57
La		 58
Ce		 59
Pr		 60
Nd		 61
Pm		 62
Sm		 63
Eu		 64
Gd		 65
Tb		 66
Dy		 67
Ho		 68
Er		 69
Tm		 70
Yb		 71
Lu
*2 アクチノイド 89
Ac		 90
Th		 91
Pa		 92
U		 93
Np		 94
Pu		 95
Am		 96
Cm		 97
Bk		 98
Cf		 99
Es		 100
Fm		 101
Md		 102
No		 103
Lr

原子番号
元素記号
英語名
和名
原子量
1
H
 hydrogen 水素
1.008
2
He
 helium ヘリウム
4.003
3
Li
 lithium リチウム
6.941
4
Be
 beryllium ベリリウム
9.012
5
B
 boron ホウ素（硼素）
10.81
6
C
 carbon 炭素
12.01
7
N
 nitrogen 窒素
14.01
8
O
 oxygen 酸素
16.00
9
F
 fluorine フッ素（弗素）
19.00
10
Ne
 neon ネオン
20.18
 戻る
11
Na
 sodium ナトリウム
22.99
12
Mg
 magnesium マグネシウム
24.31
13
Al
 aluminum アルミニウム
26.98
14
Si
 silicon ケイ素（硅素）
28.09
15
P
 phosphorus リン（燐）
30.97
16
S
 sulfur 硫黄
32.07
17
Cl
 chlorine 塩素
35.45
18
Ar
 argon アルゴン
39.95
19
K
 potassium カリウム
39.10
20
Ca
 calcium カルシウム
40.08
21
Sc
 scandium スカンジウム
44.96
22
Ti
 titanium チタン
47.88
23
V
 vanadium バナジウム
50.94
24
Cr
 chromium クロム
52.00
25
Mn
 manganese マンガン
54.94
26
Fe
 iron 鉄
55.85
27
Co
 cobalt コバルト
58.93
28
Ni
 nickel ニッケル
58.69
29
Cu
 copper 銅
63.55
30
Zn
 zinc 亜鉛
65.39
31
Ga
 gallium ガリウム
69.72
32
Ge
 germanium ゲルマニウム
72.61
33
As
 arsenic ヒ素（砒素）
74.92
34
Se
 selenium セレン
78.96
35
Br
 bromine 臭素
79.90
36
Kr
 krypton クリプトン
83.80
37
Rb
 rubidium ルビジウム
85.47
38
Sr
 strontium ストロンチウム
87.62
39
Y
 yttrium イットリウム
88.91
40
Zr
 zirconium ジルコニウム
91.22
41
Nb
 niobium ニオブ
92.91
42
Mo
 molybdenum モリブデン
95.94
43
Tc
 technetium テクネチウム
放射性
44
Ru
 ruthenium ルテニウム
101.1
45
Rh
 rhodium ロジウム
102.9
46
Pd
 palladium パラジウム
106.4
47
Ag
 silver 銀
107.9
48
Cd
 cadmium カドミウム
112.4
49
In
 indium インジウム
114.8
50
Sn
 tin スズ（錫）
118.7
51
Sb
 antimony アンチモン
121.8
52
Te
 tellurium テルル
127.6
53
I
 iodine ヨウ素（沃素）
126.9
54
Xe
 xenon キセノン
131.3
55
Cs
 cesium セシウム
132.9
56
Ba
 barium バリウム
137.3
57
La
 lanthanum ランタン
138.9
58
Ce
 cerium セリウム
140.1
62
Sm
 samarium サマリウム
150.4
63
Eu
 europium ユーロピウム
64
Gd
 gadolinium ガドリニウム
157.3
70
Yb
 ytterbium イッテルビウム
173.0
72
Hf
 hafnium ハフニウム
178.5
73
Ta
 tantalum タンタル
180.9
74
W
 tungsten タングステン
183.9
75
Re
 rhenium レニウム
186.2
76
Os
 osmium オスミウム
190.2
77
Ir
 iridium イリジウム
192.2
78
Pt
 platinum 白金（プラチナ）
195.1
79
Au
 gold 金
197.0
80
Hg
 mercury 水銀
200.6
81
Tl
 thallium タリウム
204.4
82
Pb
 lead 鉛
207.2
83
Bi
 bismuth ビスマス
209.0
86
Rn
 radon ラドン
放射性
88
Ra
 radium ラジウム
放射性
92
U
 uranium ウラニウム
238.0
94
Pu
 plutonium プルトニウム
放射性

Virtual Textbook of Organic Chemistry
by Professor William H. Reusch (Michigan State University)

　ミシガン州立大学化学科教授・William H. Reusch先生のご厚意により、インターネット上に公開されている有機化学教科書「Virtual Textbook of Organic Chemistry」のテキストの一部を使わせていただけた。有機化学の基礎的な概念が手際よく平易な英語の文章で綴られており、反復学習することによって「有機化学英語」はもちろん、有機化学そのものの実力がつくことは間違いない。さらに「平易な」英語で有機化学を勉強したい方はReusch先生のサイトを訪問されることを強くお勧めしたい。

Electronegativity The Shape of Molecules
Resonance Solubility in Water
Reaction Variables Mechanisms of Organic Reactions
Examples of Organic Reactions Bond Energy
Reaction Energetics Stereoisomers
Reactions of Alkenes Free Radical Reactions
Reactions of Alkynes Reactions of Alkyl Halides
Bredt's Rule Reactions of Alcohols
Reactions of Phenols Reactions of Ethers
Chemistry of Epoxides Sulfur and Phosphorus Compounds
Aromatic Substitution Reactions Important Reagent Bases
Aryl Amines & Aryl Diazonium Salts Acetal Formation
Imines & Enamines Irreversible Addition Reactions
Alkylation Reactions of Enolates Acidity of Carboxylic Acids
Acyl Group Substitution Carboxylic Acids Derivatives
Enolate Intermediates Heterocyclic Compounds

Electronegativity
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Polar Covalent Bonds

Because of their differing nuclear charges, and as a result of shielding by inner electron shells, the different atoms of the periodic table have different affinities for nearby electrons. The ability of an element to attract or hold onto electrons is called electronegativity.

A rough quantitative scale of electronegativity values was established by Linus Pauling, and some of these are given in the table to the right.

A larger number on this scale signifies a greater affinity for electrons. Fluorine has the greatest electronegativity of all the elements, and the heavier alkali metals such as potassium, rubidium and cesium have the lowest electronegativities.

It should be noted that carbon is about in the middle of the electronegativity range, and is slightly more electronegative than hydrogen.

When two different atoms are bonded covalently, the shared electrons are attracted to the more electronegative atom of the bond, resulting in a shift of electron density toward the more electronegative atom. Such a covalent bond is polar, and will have a dipole (one end is positive and the other end negative).

The degree of polarity and the magnitude of the bond dipole will be proportional to the difference in electronegativity of the bonded atoms. Thus an O–H bond is more polar than a C–H bond, with the hydrogen atom of the former being more positive than the hydrogen bonded to carbon.

Likewise, C–Cl and C–Li bonds are both polar, but the carbon end is positive in the former and negative in the latter. The dipolar nature of these bonds is often indicated by a partial charge notation (δ+/–) or by an arrow pointing to the negative end of the bond.

Although there is a small electronegativity difference between carbon and hydrogen, the C–H bond is regarded as weakly polar at best, and hydrocarbons in general are considered to be non-polar compounds.

The shift of electron density in a covalent bond toward the more electronegative atom or group can be observed in several ways. For bonds to hydrogen, acidity is one criterion. If the bonding electron pair moves away from the hydrogen nucleus the proton will be more easily transfered to a base (it will be more acidic).

A comparison of the acidities of methane, water and hydrofluoric acid is instructive. Methane is essentially non-acidic, since the C–H bond is nearly non-polar. As noted above, the O–H bond of water is polar, and it is at least 25 powers of ten more acidic than methane. H–F is over 12 powers of ten more acidic than water as a consequence of the greater electronegativity difference in its atoms.

Electronegativity differences may be transmitted through connecting covalent bonds by an inductive effect. Replacing one of the hydrogens of water by a more electronegative atom increases the acidity of the remaining O–H bond.

Thus hydrogen peroxide, HO–O–H, is ten thousand times more acidic than water, and hypochlorous acid, Cl–O–H is one hundred million times more acidic. This inductive transfer of polarity tapers off as the number of transmitting bonds increases, and the presence of more than one highly electronegative atom has a cumulative effect. For example, trifluoro ethanol, CF3CH2–O–H is about ten thousand times more acidic than ethanol, CH3CH2–O–H.

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Molecular Shape
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The Shape of Molecules

The three dimensional shape or configuration of a molecule is an important characteristic. This shape is dependent on the preferred spatial orientation of covalent bonds to atoms having two or more bonding partners. Three dimensional configurations are best viewed with the aid of models.

In order to represent such configurations on a two-dimensional surface (paper, blackboard or screen), we often use perspective drawings in which the direction of a bond is specified by the line connecting the bonded atoms.

In most cases the focus of configuration is a carbon atom so the lines specifying bond directions will originate there. As defined in the diagram on the right, a simple straight line represents a bond lying approximately in the surface plane. The two bonds to substituents A in the structure on the left are of this kind. A wedge shaped bond is directed in front of this plane (thick end toward the viewer), as shown by the bond to substituent B; and a hatched bond is directed in back of the plane (away from the viewer), as shown by the bond to substituent D.

The following examples make use of this notation, and also illustrate the importance of including non-bonding valence shell electron pairs (colored blue) when viewing such configurations .

Bonding configurations are readily predicted by valence-shell electron-pair repulsion theory, commonly referred to as VSEPR in most introductory chemistry texts. This simple model is based on the fact that electrons repel each other, and that it is reasonable to expect that the bonds and non-bonding valence electron pairs associated with a given atom will prefer to be as far apart as possible. The bonding configurations of carbon are easy to remember, since there are only three categories.

In the three examples shown above, the central atom (carbon) does not have any non-bonding valence electrons; consequently the configuration may be estimated from the number of bonding partners alone.

For molecules of water and ammonia, however, the non-bonding electrons must be included in the calculation. In each case there are four regions of electron density associated with the valence shell so that a tetrahedral bond angle is expected.

The measured bond angles of these compounds (H2O 104.5º & NH3 107.3º) show that they are closer to being tetrahedral than trigonal or linear. Of course, it is the configuration of atoms (not electrons) that defines the the shape of a molecule, and in this sense ammonia is said to be pyramidal (not tetrahedral). The compound boron trifluoride, BF3, does not have non-bonding valence electrons and the configuration of its atoms is trigonal.

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Resonance
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Resonance

Kekulé structural formulas are essential tools for understanding organic chemistry. However, the structures of some compounds and ions cannot be represented by a single formula. For example, sulfur dioxide (SO2) and nitric acid (HNO3) may each be described by two equivalent formulas (equations 1 & 2). For clarity the two ambiguous bonds to oxygen are given different colors in these formulas.

If only one formula for sulfur dioxide was correct and accurate, then the double bond to oxygen would be shorter and stronger than the single bond. Since experimental evidence indicates that this molecule is bent (bond angle 120º) and has equal length sulfur : oxygen bonds (1.432 Å), a single formula is inadequate, and the actual structure resembles an average of the two formulas.

This averaging of electron distribution over two or more hypothetical contributing structures (canonical forms) to produce a hybrid electronic structure is called resonance. Likewise, the structure of nitric acid is best described as a resonance hybrid of two structures, the double headed arrow being the unique symbol for resonance.

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Water Solubility
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Solubility in Water

Water has been referred to as the "universal solvent", and its widespread distribution on this planet and essential role in life make it the benchmark for discussions of solubility. Water dissolves many ionic salts thanks to its high dielectric constant and ability to solvate ions. The former reduces the attraction between oppositely charged ions and the latter stabilizes the ions by binding to them and delocalizing charge density.

Many organic compounds, especially alkanes and other hydrocarbons, are nearly insoluble in water. Organic compounds that are water soluble, such as most of those listed in the table below, generally have hydrogen bond acceptor and donor groups.

The least soluble of the listed compounds is diethyl ether, which can serve only as a hydrogen bond acceptor and is 75% hydrocarbon in nature. Even so, diethyl ether is about two hundred times more soluble in water than is pentane.

The chief characteristic of water that influences these solubilities is the extensive hydrogen bonded association of its molecules with each other. This hydrogen bonded network is stabilized by the sum of all the hydrogen bond energies, and if nonpolar molecules such as hexane were inserted into the network they would destroy local structure without contributing any hydrogen bonds of their own.

Of course, hexane molecules experience significant van der Waals attraction to neighboring molecules, but these attractive forces are much weaker than the hydrogen bond. Consequently, when hexane or other nonpolar compounds are mixed with water, the strong association forces of the water network exclude the nonpolar molecules, which must then exist in a separate phase. This is shown in the following illustration, and since hexane is less dense than water, the hexane phase floats on the water phase.

It is important to remember this tendency of water to exclude nonpolar molecules and groups, since it is a factor in the structure and behavior of many complex molecular systems. A common nomenclature used to describe molecules and regions within molecules is hydrophilic for polar, hydrogen bonding moieties and hydrophobic for nonpolar species.

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Reaction Variables

The Variables of Organic Reactions

In an effort to understand how and why reactions of functional groups take place in the way they do, chemists try to discover just how different molecules and ions interact with each other as they come together.

To this end, it is important to consider the various properties and characteristics of a reaction that may be observed and/or measured as the reaction proceeds . The most common and useful of these are listed below:

1. Reactants and Reagents

A. Reactant Structure: Variations in the structure of the reactant may have a marked influence on the course of a reaction, even though the functional group is unchanged. Thus, reaction of 1-bromopropane with sodium cyanide proceeds smoothly to yield butanenitrile, whereas 1-bromo-2,2-dimethylpropane fails to give any product and is recovered unchanged. In contrast, both alkyl bromides form Grignard reagents (RMgBr) on reaction with magnesium.

B. Reagent Characteristics: Apparently minor changes in a reagent may lead to a significant change in the course of a reaction. For example, 2-bromopropane gives a substitution reaction with sodium methylthiolate but undergoes predominant elimination on treatment with sodium methoxide.

2. Product Selectivity

A. Regioselectivity: It is often the case that addition and elimination reactions may, in principle, proceed to more than one product. Thus 1-butene might add HBr to give either 1-bromobutane or 2-bromobutane, depending on which carbon of the double bond receives the hydrogen and which the bromine. If one possible product out of two or more is formed preferentially, the reaction is said to be regioselective.

Simple substitution reactions are not normally considered regioselective, since by definition only one constitutional product is possible. However, rearrangements are known to occur during some reactions.

B. Stereoselectivity: If the reaction products are such that stereoisomers may be formed, a reaction that yields one stereoisomer preferentially is said to be stereoselective.

In the addition of bromine to cyclohexene, for example, cis and trans-1,2-dibromocyclohexane are both possible products of the addition. Since the trans-isomer is the only isolated product, this reaction is stereoselective.

C. Stereospecificity: This term is applied to cases in which stereoisomeric reactants behave differently in a given reaction. Examples include:

(i) Formation of different stereoisomeric products, as in the reaction of enantiomeric 2-bromobutane isomers with sodium methylthiolate, shown in the following diagram.

Here, the (R)-reactant gives the configurationally inverted (S)-product, and (S)-reactant produces (R)-product.

(ii) Different rates of reaction, as in the base-induced elimination of cis & trans-4-tert-butylcyclohexyl bromide (equation 1 below).

(iii) Different reaction paths leading to different products, as in the base-induced eleimination of cis & trans-2-methylcyclohexyl bromide (equation 2 below).

3. Reaction Characteristics

A. Reaction Rates: Some reactions proceed very rapidly, and some so slowly that they are not normally observed. Among the variables that influence reaction rates are temperature (reactions are usually faster at a higher temperature), solvent, and reactant / reagent concentrations.

Useful information about reaction mechanisms may be obtained by studying the manner in which the rate of a reaction changes as the concentrations of the reactant and reagents are varied. This field of study is called kinetics.

B. Intermediates: Many reactions proceed in a stepwise fashion. This can be convincingly demonstrated if an intermediate species can be isolated and shown to proceed to the same products under the reaction conditions.

Some intermediates are stable compounds in their own right; however, some are so reactive that isolation is not possible. Nevertheless, evidence for their existence may be obtained by other means, including spectroscopic observation or inference from kinetic results.

4. Factors that Influence Reactions

It is helpful to identify some general features of a reaction that have a significant influence on its facility. Some of the most important of these are:

A. Energetics: The potential energy of a reacting system changes as the reaction progresses. The overall change may be exothermic ( energy is released ) or endothermic ( energy must be added ), and there is usually an activation energy requirement as well.

Tables of Standard Bond Energies are widely used by chemists for estimating the energy change in a proposed reaction. As a rule, compounds constructed of strong covalent bonds are more stable than compounds incorporating one or more relatively weak bonds.

B. Electronic Effects: The distribution of electrons at sites of reaction (functional groups) is a particularly important factor. Electron deficient species or groups, which may or may not be positively charged, are attracted to electron rich species or groups, which may or may not be negatively charged. We refer to these species as electrophiles & nucleophiles respectively. In general, opposites attract and like repel.

The charge distribution in a molecule is usually discussed with respect to two interacting effects: An inductive effect, which is a function of the electronegativity differences that exist between atoms (and groups); and a resonance effect, in which electrons move in a discontinuous fashion between parts of a molecule.

C. Steric Effects: Atoms occupy space. When they are crowded together, van der Waals repulsions produce an unfavorable steric hindrance. Steric hindrance may influence conformational equilibria, as well as destabilizing transition states of reactions.

D. Stereoelectronic Effects: In many reactions atomic or molecular orbitals interact in a manner that has an optimal configurational or geometrical alignment. Departure from this alignment inhibits the reaction.

E. Solvent Effects: Most reactions are conducted in solution, not in a gaseous state. The solvent selected for a given reaction may exert a strong influence on its course. Remember, solvents are chemicals, and most undergo chemical reaction under the right conditions.
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Reaction Mechanisms
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Mechanisms of Organic Reactions

A detailed description of the changes in structure and bonding that take place in the course of a reaction, and the sequence of such events is called the reaction mechanism. A reaction mechanism should include a representation of plausible electron reorganization, as well as the identification of any intermediate species that may be formed as the reaction progresses. These features are elaborated in the following sections.

1. The Arrow Notation in Mechanisms

Since chemical reactions involve the breaking and making of bonds, a consideration of the movement of bonding ( and non-bonding ) valence shell electrons is essential to this understanding.

It is now common practice to show the movement of electrons with curved arrows, and a sequence of equations depicting the consequences of such electron shifts is termed a mechanism. In general, two kinds of curved arrows are used in drawing mechanisms:

A full head on the arrow indicates the movement or shift of an electron pair:
A partial head (fishhook) on the arrow indicates the shift of a single electron:

The use of these symbols in bond-breaking and bond-making reactions is illustrated below. If a covalent single bond is broken so that one electron of the shared pair remains with each fragment, as in the first example, this bond-breaking is called homolysis.

If the bond breaks with both electrons of the shared pair remaining with one fragment, as in the second and third examples, this is called heterolysis.

Other Arrow Symbols

Chemists also use arrow symbols for other purposes, and it is essential to use them correctly.

The following equations illustrate the proper use of these symbols:

2. Reactive Intermediates

The products of bond breaking, shown above, are not stable in the usual sense, and cannot be isolated for prolonged study. Such species are referred to as reactive intermediates, and are believed to be transient intermediates in many reactions. The general structures and names of four such intermediates are given below.

A pair of widely used terms, related to the Lewis acid-base notation, should also be introduced here.

Electrophile: An electron deficient atom, ion or molecule that has an affinity for an electron pair,and will bond to a base or nucleophile.
Nucleophile: An atom, ion or molecule that has an electron pair that may be donated in bonding to an electrophile (or Lewis acid).

Using these definitions, it is clear that carbocations ( called carbonium ions in the older literature ) are electrophiles and carbanions are nucleophiles. Carbenes have only a valence shell sextet of electrons and are therefore electron deficient. In this sense they are electrophiles, but the non-bonding electron pair also gives carbenes nucleophilic character. As a rule, the electrophilic character dominates carbene reactivity.

Carbon radicals have only seven valence electrons, and may be considered electron deficient; however, they do not in general bond to nucleophilic electron pairs, so their chemistry exhibits unique differences from that of conventional electrophiles. Radical intermediates are often called free radicals.

The importance of electrophile / nucleophile terminology comes from the fact that many organic reactions involve at some stage the bonding of a nucleophile to an electrophile, a process that generally leads to a stable intermediate or product. Reactions of this kind are sometimes called ionic reactions, since ionic reactants or products are often involved.

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Reaction Examples
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Examples of Organic Reactions

1. Ionic Reactions

The principles and terms introduced in the previous sections can now be summarized and illustrated by the following three examples. Reactions such as these are called ionic or polar reactions, because they often involve charged species and the bonding together of electrophiles and nucleophiles. Ionic reactions normally take place in liquid solutions, where solvent molecules assist the formation of charged intermediates.

　

The substitution reaction shown on the left can be viewed as taking place in three steps. The first is an acid-base equilibrium, in which HCl protonates the oxygen atom of the alcohol. The resulting conjugate acid then loses water in a second step to give a carbocation intermediate. Finally, this electrophile combines with the chloride anion nucleophile to give the final product.

The addition reaction shown on the left can be viewed as taking place in two steps. The first step can again be considered an acid-base equilibrium, with the pi-electrons of the carbon-carbon double bond functioning as a base. The resulting conjugate acid is a carbocation, and this electrophile combines with the nucleophilic bromide anion.

The elimination reaction shown on the left takes place in one step. The bond breaking and making operations that take place in this step are described by the curved arrows. The initial stage may also be viewed as an acid-base interaction, with hydroxide ion serving as the base and a hydrogen atom component of the alkyl chloride as an acid.

There are many kinds of molecular rearrangements. The examples shown on the left are from an important class called tautomerization or, more specifically, keto-enol tautomerization.

Tautomers are rapidly interconverted constitutional isomers, usually distinguished by a different bonding location for a labile hydrogen atom (colored red here) and a differently located double bond.

The equilibrium between tautomers is not only rapid under normal conditions, but it often strongly favors one of the isomers (acetone, for example, is 99.999% keto tautomer). Even in such one-sided equilibria, evidence for the presence of the minor tautomer comes from the chemical behavior of the compound.

Tautomeric equilibria are catalyzed by traces of acids or bases that are generally present in most chemical samples.

2. Radical Reactions

If methane gas is mixed with chlorine gas and exposed to sunlight an explosive reaction takes place in which chlorinated methane products are produced along with hydrogen chloride. An unbalanced equation illustrating this reaction is shown below; the relative amounts of the various products depends on the proportion of the two reactants that are used.

How does this reaction take place? Gas phase reactions, such as the chlorination of methane, do not normally proceed via ionic intermediates. Strong evidence indicates that neutral radical intermediates, sometimes called free radicals, play a role in this and many other similar transformations.

A radical is an atomic or molecular species having an unpaired, or odd, electron. Some radicals, such as nitrogen dioxide (NO2) and nitric oxide (NO) are relatively stable, but most are so reactive that isolation and long-term study under normal conditions is not possible.

A set of radical reactions called a chain reaction can account for all the facts observed for this process.

The reaction is initiated by the input of energy (heat or light). The weak chlorine-chlorine bond is broken homolytically to give chlorine atoms.

In these two reactions radical intermediates abstract an atom from one of the reactant molecules. If a chlorine atom abstracts a hydrogen from methane in the first step, the resulting methyl radical abstracts a chlorine atom from chlorine in the second step, regenerating a chlorine atom. This is therefore a chain reaction.

In principle a chain reaction should continue until one or both of the reactants are consumed. In practice, however, such reactions stop before completion and have to be reinitiated.

This happens whenever two radical intermediates meet and combine to give a stable molecule, thus terminating the chain of reactions.

Since radical intermediates are extremely reactive and are present in very low concentration, the probability that two such intermediates will collide is small. Consequently, the chain reaction will proceed through many cycles before termination occurs.
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Bond Energy
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Bond Energy

Since reactions of organic compounds involve the making and breaking of bonds, the strength of bonds, or their resistance to breaking, becomes an important consideration. For example, the chlorination of methane, discussed previously, was induced by breaking a relatively weak Cl-Cl covalent bond.

Bond energy is the energy required to break a covalent bond homolytically (into neutral fragments). Bond energies are commonly given in units of kcal/mol or kJ/mol, and are generally called bond dissociation energies when given for specific bonds, or average bond energies when summarized for a given type of bond over many kinds of compounds.

Tables of bond energies may be found in most text books and handbooks. The following table is a collection of average bond energies for a variety of common bonds. Such average values are often referred to as standard bond energies, and are given here in units of kcal/mole.

The SI unit of energy is the joule, symbol J. To convert kilocalories into kilojoules multiply by 4.184. A useful site for unit conversions may be reached by Clicking Here.


* Average Bond Dissociation Enthalpies in kcal mole-1

Some useful and interesting conclusions may be drawn from this table. First, a single bond between two given atoms is weaker than a double bond, which in turn is weaker than a triple bond.

Second, hydrogen forms relatively strong bonds (90 to 110 kcal) to the common elements found in organic compounds (C, N & O).

Third, with the exception of carbon and hydrogen, single bonds between atoms of the same element are relatively weak (35 to 64 kcal).

Indeed, the fact that carbon forms relatively strong bonds to itself as well as to nitrogen, oxygen and hydrogen is a primary factor accounting for the very large number of stable organic compounds.

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Energetics
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Reaction Energetics

Chemical reactions involve breaking and making some (or even all) of the bonds that hold together the atoms of reactant and product molecules. Energy is required to break bonds, and since the strengths of different kinds of bonds differ, there is often a significant overall energy change in the course of a reaction.

In the combustion of methane, for example, all six bonds in the reactant molecules are broken, and six new bonds are formed in the product molecules (equation 1).

The sum of the product bond strengths in this case is greater than the sum of reactant bond strengths; consequently, the products are energetically (or thermodynamically) more stable than the reactants, and energy is released in the form of heat. Such reactions are called exothermic.

It is helpful to think of exothermic reactions as proceeding from a higher energy (less stable) reactant state to a lower energy (more stable) product state, as shown in the diagram on the right.

Reactions in which the products are higher energy than the reactants require an energy input to occur, and are called endothermic. Photosynthesis (equation 2) is an important example of an endothermic process. Energy in the form of photons (sunlight) drives the reaction, which requires chlorophyll as a catalyst.

Common sense suggests that molecules in which the bonds are all strong will be more stable than molecules having weaker bonds. Previously we defined bond strengths as the energy required to break a bond into neutral fragments (radicals or atoms).

The sum of all the bond energies of a molecule can therefore be considered its atomization energy, i.e. the energy required to break the molecule completely into its component atoms. If this concept is applied to a group of isomers, it should be clear that all the isomers will have a common atomization state, and that the total bond energy of each isomer is inversely related to that isomer's potential energy.

Thus, that isomer having the greatest total bond energy has the lowest potential energy and is thermodynamically most stable. To summarize, bond energy is energy that must be introduced to break a bond, and is not a component of a molecule's potential energy.

The three C6H12 isomers on the right illustrate this relationship. Cyclohexane is made up of six C-C sigma bonds and twelve C-H sigma bonds configured in a strain-free six-membered ring.

The isomer having a double bond, 1-hexene, on the other hand, has four C-C single bonds (all sigma) and one C-C double bond (one sigma and one pi bond). Since the pi bond is weaker than a sigma bond, cyclohexane has a larger total bond energy (by nearly 20 kcal/mol) and is thermodynamically more stable than 1-hexene.

The four-membered ring compound, ethylcyclobutane, has the same kinds of bonds as cyclohexane, but they are weakened by ring strain to such a degree that this isomer is even less stable (thermodynamically) than 1-hexene.

1. Activation Energy

Since exothermic reactions are energetically (thermodynamically) favored, a careless thinker might conclude that all such reactions will proceed spontaneously to their products.

Were this true, no life would exist on Earth, because the numerous carbon compounds that are present in and essential to all living organisms would spontaneously combust in the presence of oxygen to give carbon dioxide-a more stable carbon compound.

The combustion of methane (eq.1), for example, does not occur spontaneously, but requires an initiating energy in the form of a spark or flame. The flaw in this careless reasoning is that we have focused only on the initial (reactant) and final (product) states of reactions.

To understand why some reactions occur readily (almost spontaneously), whereas other reactions are slow, even to the point of being unobservable, we need to consider the intermediate stages of reactions.

Every reaction in which bonds are broken will have a high energy transition state that must be reached before products can form. In order for the reactants to reach this transition state, energy must be supplied and reactant molecules must orient themselves in a suitable fashion.

The energy needed to raise the reactants to the transition state energy level is called the activation energy, ΔE‡. An example of a single-step exothermic reaction profile is shown on the left above, and a similar single-step profile for an endothermic reaction is in the center. The activation energy is drawn in red in each case, and the overall energy change (ΔE) is in green.

The profile becomes more complex when a multi-step reaction path is described. An example of a two-step reaction proceeding by way of a high energy intermediate is shown on the right above.

Here there are two transition states, each with its own activation energy. The overall activation energy is the difference in energy between the reactant state and the highest energy transition state. We see now why the rate of a reaction may not correlate with its overall energy change.

In the exothermic diagram on the left, a significant activation energy must be provided to initiate the reaction. Since the reaction is strongly exothermic, it will probably generate enough heat to keep going as long as reactants remain.

The endothermic reaction in the center has a similar activation energy, but heat will have to be supplied continuously for the reaction to proceed to completion.

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Stereoisomers
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Stereoisomers

As defined in an earlier introductory section, isomers are different compounds that have the same molecular formula. When the group of atoms that make up the molecules of different isomers are bonded together in fundamentally different ways, we refer to such compounds as constitutional isomers.

For example, in the case of the C4H8 hydrocarbons, most of the isomers are constitutional. Shorthand structures for four of these isomers are shown below with their IUPAC names.

Note that the twelve atoms that make up these isomers are connected or bonded in very different ways. As is true for all constitutional isomers, each different compound has a different IUPAC name. Furthermore, the molecular formula provides information about some of the structural features that must be present in the isomers.

Since the formula C4H8 has two fewer hydrogens than the four-carbon alkane butane (C4H10), all the isomers having this composition must incorporate either a ring or a double bond. A fifth possible isomer of formula C4H8 is CH3CH=CHCH3.

This would be named 2-butene according to the IUPAC rules; however, a close inspection of this molecule indicates it has two possible structures. These isomers may be isolated as distinct compounds, having characteristic and different properties. They are shown here with the designations cis and trans.

The bonding patterns of the atoms in these two isomers are essentially equivalent, the only difference being the relative orientation or configuration of the two methyl groups (and the two associated hydrogen atoms) about the double bond.

In the cis isomer the methyl groups are on the same side; whereas they are on opposite sides in the trans isomer. Isomers that differ only in the spatial orientation of their component atoms are called stereoisomers.

Stereoisomers always require that an additional nomenclature prefix be added to the IUPAC name in order to indicate their spatial orientation, for example, cis (Latin, meaning on this side) and trans (Latin, meaning across) in the 2-butene case.
Stereoisomers II

As chemists studied organic compounds isolated from plants and animals, a new and subtle type of configurational stereoisomerism was discovered.

For example, lactic acid ( a C3H6O3 carboxylic acid) was found in sour milk as well as in the blood and muscle fluids of animals. The physical properties of this simple compound were identical, regardless of the source (m.p, 53 ºC & pKa 3.80), but there was evidence that the physiological behavior of the compound from the two sources was not the same.

Another natural product, the fragrant C10H14O ketone carvone, was isolated from both spearmint and caraway. Again, all the physical properties of carvone from these two sources seemed to be identical (b.p. 230 ºC), but the odors of the two carvones were different and reflected their source.

Other examples of this kind were encountered, and suspicions of a subtle kind of stereoisomerism were confirmed by the different interaction these compounds displayed with plane polarized light.

We now know that this configurational stereoisomerism is due to different right and left-handed forms that certain structures may adopt, in much the same way that a screw may have right or left-handed threads but the same overall size and shape. Isomeric pairs of this kind are termed enantiomers (from the Greek enantion meaning opposite).

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Reactions of Alkenes
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2. Addition Reactions Initiated by Electrophilic Halogen

The halogens chlorine and bromine add rapidly to a wide variety of alkenes without inducing the kinds of structural rearrangements noted for strong acids (first example below). The stereoselectivity of these additions is strongly anti, as shown in many of the following examples.

An important principle should be restated at this time. The alkenes shown here are all achiral, but the addition products have chiral centers, and in many cases may exist as enantiomeric stereoisomers.

In the absence of chiral catalysts or reagents, reactions of this kind will always give racemic mixtures if the products are enantiomeric. On the other hand, if two chiral centers are formed in the addition the reaction will be diastereomer selective. This is clearly shown by the addition of bromine to the isomeric 2-butenes. Anti-addition to cis-2-butene gives the racemic product, whereas anti-addition to the trans-isomer gives the meso-diastereomer.

We can account both for the high stereoselectivity and the lack of rearrangement in these reactions by proposing a stabilizing interaction between the developing carbocation center and the electron rich halogen atom on the adjacent carbon.

This interaction, which is depicted for bromine in the following equation, delocalizes the positive charge on the intermediate and blocks halide ion attack from the syn-location.

The stabilization provided by this halogen-carbocation bonding makes rearrangement unlikely. In a few cases three-membered cyclic halonium cations have been isolated and identified as true intermediates.

A resonance description of such a bromonium ion intermediate is shown below. The positive charge is delocalized over all the atoms of the ring, but should be concentrated at the more substituted carbon (carbocation stability), and this is the site to which the nucleophile will bond.

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Free Radical Reactions
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2. Allylic Substitution

We noted earlier that benzylic and allylic sites are exceptionally reactive in free radical halogenation reactions. Since carbon-carbon double bonds add chlorine and bromine in liquid phase solutions, radical substitution reactions by these halogens are often carried out at elevated tempreature in the gas phase (first equation below).

Formation of the ionic π-complexes that are intermediates in halogen addition is unfavorable in the absence of polar solvents, and entropy generally favors substitution over addition.

The brominating reagent, N-bromosuccinimide (NBS), has proven useful for achieving allylic or benzylic substitution in CCl4 at temperatures below its boiling point (77 °C). One such application is shown in the second equation.

The predominance of allylic substitution over addition in the NBS reaction is interesting. The N–Br bond is undoubtedly weak (probably less than 50 kcal/mol) so bromine atom abstraction by radicals should be very favorable. The resulting succinimyl radical might then establish a chain reaction by removing an allylic hydrogen from the alkene.

One problem with this mechanism is that NBS is very insoluble in CCl4, about 0.006 mole / liter at reflux. Although it is possible that the allylic bromination occurs at a solid-liquid interface, evidence for another pathway has been obtained.

In the non-polar solvent used for these reactions, very low concentrations of bromine may be generated from NBS. This would serve as a source of bromine atoms, which would abstract allylic hydrogens irreversibly (an exothermic reaction) in competition with reversible addition to the double bond.

The HBr produced in this way is known to react with NBS, giving a new bromine molecule and succinimide, as shown here. Ionic addition of bromine to the double bond would be very slow in these circumstances.

This mechanism is essentially the same as that for the free radical halogenation of alkanes, with NBS serving as a source of very low concentrations of bromine.

Unsymmetrical allylic radicals will react to give two regioisomers. Thus, 1-octene on bromination with NBS yields a mixture of 3-bromo-1-octene (ca. 18%) and 1-bromo-2-octene (82%) - both cis and trans isomers.

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Reactions of Alkynes
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Addition Reactions of Alkynes

A carbon-carbon triple bond may be located at any unbranched site within a carbon chain or at the end of a chain, in which case it is called terminal. Because of its linear configuration ( the bond angle of a sp-hybridized carbon is 180º ), a ten-membered carbon ring is the smallest that can accomodate this function without excessive strain.

Since the most common chemical transformation of a carbon-carbon double bond is an addition reaction, we might expect the same to be true for carbon-carbon triple bonds. Indeed, most of the alkene addition reactions discussed earlier also take place with alkynes, and with similar regio- and stereoselectivity.

1. Catalytic Hydrogenation

The catalytic addition of hydrogen to 2-butyne not only serves as an example of such an addition reaction, but also provides heat of reaction data that reflect the relative thermodynamic stabilities of these hydrocarbons, as shown in the diagram to the right.

From the heats of hydrogenation, shown in blue in units of kcal/mole, it would appear that alkynes are thermodynamically less stable than alkenes to a greater degree than alkenes are less stable than alkanes.

The standard bond energies for carbon-carbon bonds confirm this conclusion. Thus, a double bond is stronger than a single bond, but not twice as strong. The difference ( 63 kcal/mole ) may be regarded as the strength of the π-bond component.

Similarly, a triple bond is stronger than a double bond, but not 50% stronger. Here the difference ( 54 kcal/mole ) may be taken as the strength of the second π-bond. The 9 kcal/mole weakening of this second π-bond is reflected in the heat of hydrogenation numbers ( 36.7 - 28.3 = 8.4 ).

Since alkynes are thermodynamically less stable than alkenes, we might expect addition reactions of the former to be more exothermic and relatively faster than equivalent reactions of the latter.

In the case of catalytic hydrogenation, the usual Pt and Pd hydrogenation catalysts are so effective in promoting addition of hydrogen to both double and triple carbon-carbon bonds that the alkene intermediate formed by hydrogen addition to an alkyne cannot be isolated.

A less efficient catalyst, Lindlar's catalyst, prepared by deactivating (or poisoning) a conventional palladium catalyst by treating it with lead acetate and quinoline, permits alkynes to be converted to alkenes without further reduction to an alkane.

The addition of hydrogen is stereoselectively syn (e.g. 2-butyne gives cis-2-butene). A complementary stereoselective reduction in the anti mode may be accomplished by a solution of sodium in liquid ammonia.

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Reactions of Alkyl Halides
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Alkyl Halide Reactions

The functional group of alkyl halides is a carbon-halogen bond, the common halogens being fluorine, chlorine, bromine and iodine. With the exception of iodine, these halogens have electronegativities significantly greater than carbon.

Consequently, this functional group is polarized so that the carbon is electrophilic and the halogen is nucleophilic, as shown in the drawing on the right.

Two characteristics other than electronegativity have an important influence on the chemical behavior of these compounds. The first of these is covalent bond strength. The strongest of the carbon-halogen covalent bonds is that to fluorine.

Remarkably, this is the strongest common single bond to carbon, being roughly 30 kcal/mole stronger than a carbon-carbon bond and about 15 kcal/mole stronger than a carbon-hydrogen bond. Because of this, alkyl fluorides and fluorocarbons in general are chemically and thermodynamically quite stable, and do not share any of the reactivity patterns shown by the other alkyl halides.

The carbon-chlorine covalent bond is slightly weaker than a carbon-carbon bond, and the bonds to the other halogens are weaker still, the bond to iodine being about 33% weaker.

The second factor to be considered is the relative stability of the corresponding halide anions, which is likely the form in which these electronegative atoms will be replaced.

This stability may be estimated from the relative acidities of the H-X acids, assuming that the strongest acid releases the most stable conjugate base (halide anion). With the exception of HF (pKa = 3.2), all the hydrohalic acids are very strong, small differences being in the direction HCl < HBr < HI.
Substitution & Elimination

1. Nucleophilicity

Recall the definitions of electrophile and nucleophile:

Electrophile: 　 An electron deficient atom, ion or molecule that has an affinity for an electron pair, and will bond to a base or nucleophile.
Nucleophile: 　 An atom, ion or molecule that has an electron pair that may be donated in forming a covalent bond to an electrophile (or Lewis acid).

If we use a common alkyl halide, such as methyl bromide, and a common solvent, ethanol, we can examine the rate at which various nucleophiles substitute the methyl carbon. Nucleophilicity is thereby related to the relative rate of substitution reactions at the halogen-bearing carbon atom of the reference alkyl halide.

The most reactive nucleophiles are said to be more nucleophilic than less reactive members of the group. The nucleophilicities of some common Nu:(–) reactants vary as shown in the following chart.

The reactivity range encompassed by these reagents is over 5,000 fold, thiolate being the most reactive. Note that by using methyl bromide as the reference substrate, the complication of competing elimination reactions is avoided.

The nucleophiles used in this study were all anions, but this is not a necessary requirement for these substitution reactions. The cumulative results of studies of this kind has led to useful empirical rules pertaining to nucleophilicity:

(i) For a given element, negatively charged species are more nucleophilic (and basic) than are equivalent neutral species.
(ii) For a given period of the periodic table, nucleophilicity (and basicity) decreases on moving from left to right.
(iii) For a given group of the periodic table, nucleophilicity increases from top to bottom (i.e. with increasing size), although there is a solvent dependence due to hydrogen bonding. Basicity varies in the opposite manner.

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Bredt's Rule
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Bredt's Rule

The importance of maintaining a planar configuration of the trigonal double-bond carbon components must never be overlooked. For optimum pi-bonding to occur, the p-orbitals on these carbons must be parallel, and the resulting doubly-bonded planar configuration is more stable than a twisted alternative by over 60 kcal/mole.

This structural constraint is responsible for the existence of alkene stereoisomers when substitutuion patterns permit. It also prohibits certain elimination reactions of bicyclic alkyl halides, that might be favorable in simpler cases.

For example, the bicyclooctyl 3º-chloride shown below appears to be similar to tert-butyl chloride, but it does not undergo elimination, even when treated with a strong base (e.g. KOH or KOC4H9).

There are six equivalent beta-hydrogens that might be attacked by base (two of these are colored blue as a reference), so an E2 reaction seems plausible. The problem with this elimination is that the resulting double bond would be constrained in a severely twisted (non-planar) configuration by the bridged structure of the carbon skeleton.

The carbon atoms of this twisted double-bond are colored red and blue respectively, and a Newman projection looking down the twisted bond is drawn on the right. Because a pi-bond cannot be formed, the hypothetical alkene does not exist.

Structural prohibitions such as this are often encountered in small bridged ring systems, and are referred to as Bredt's Rule.

Bredt's Rule should not be applied blindly to all bridged ring systems. If large rings are present their conformational flexibility may permit good overlap of the p-orbitals of a double bond at a bridgehead.

This is similar to recognizing that trans-cycloalkenes cannot be prepared if the ring is small (3 to 7-membered), but can be isolated for larger ring systems. The anti-tumor agent taxol has such a bridgehead double bond (colored red), as shown in the following illustration.

The bicyclo[3.3.1]octane ring system is the smallest in which bridgehead double bonds have been observed. The drawing to the right of taxol shows this system. The bridgehead double bond (red) has a cis-orientation in the six-membered ring (colored blue), but a trans-orientation in the larger eight-membered ring.

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Reactions of Alcohols
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Alcohol Reactions

The functional group of the alcohols is the hydroxyl group, –OH. Unlike the alkyl halides, this group has two reactive covalent bonds, the C–O bond and the O–H bond. The electronegativity of oxygen is substantially greater than that of carbon and hydrogen.

Consequently, the covalent bonds of this functional group are polarized so that oxygen is electron rich and both carbon and hydrogen are electrophilic, as shown in the drawing on the right.

Indeed, the dipolar nature of the O–H bond is such that alcohols are much stronger acids than alkanes (by roughly 1030 times), and nearly that much stronger than ethers (oxygen substituted alkanes that do not have an O–H group).

The most reactive site in an alcohol molecule is the hydroxyl group, despite the fact that the O–H bond strength is significantly greater than that of the C–C, C–H and C–O bonds, demonstrating again the difference between thermodynamic and chemical stability.
Electrophilic Substitution at Oxygen


1. Substitution of the Hydroxyl Hydrogen

Alkyl substitution of the hydroxyl group leads to ethers. This reaction provides examples of both strong electrophilic substitution (first equation below), and weak electrophilic substitution (second equation).

The latter SN2 reaction is known as the Williamson Ether Synthesis, and is generally used only with 1º-alkyl halide reactants because the strong alkoxide base leads to E2 elimination of 2º and 3º-alkyl halides.

One of the most important substitution reactions at oxygen is ester formation resulting from the reaction of alcohols with electrophilic derivatives of carboxylic and sulfonic acids.

The following illustration displays the general formulas of these reagents and their ester products, in which the R'–O– group represents the alcohol moiety. The electrophilic atom in the acid chlorides and anhydrides is colored red.

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Phenols
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Reactions of Phenols

Compounds in which a hydroxyl group is bonded to an aromatic ring are called phenols. The chemical behavior of phenols is different in some respects from that of the alcohols, so it is sensible to treat them as a similar but characteristically distinct group.

A corresponding difference in reactivity was observed in comparing aryl halides, such as bromobenzene, with alkyl halides, such as butyl bromide and tert-butyl chloride. Thus, nucleophilic substitution and elimination reactions were common for alkyl halides, but rare with aryl halides.

This distinction carries over when comparing alcohols and phenols, so for all practical purposes substitution and/or elimination of the phenolic hydroxyl group does not occur.

1. Acidity of Phenols

On the other hand, substitution of the hydroxyl hydrogen atom is even more facile with phenols, which are roughly a million times more acidic than equivalent alcohols. This phenolic acidity is further enhanced by electron-withdrawing substituents ortho and para to the hydroxyl group, as displayed in the following diagram.

The alcohol cyclohexanol is shown for reference at the top left. It is noteworthy that the influence of a nitro substituent is over ten times stronger in the para-location than it is meta, despite the fact that the latter position is closer to the hydroxyl group.

Furthermore additional nitro groups have an additive influence if they are positioned in ortho or para locations. The trinitro compound shown at the lower right is a very strong acid called picric acid.



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Reactions of Ethers
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3. Reactions of Ethers

Ethers are widely used as solvents for a variety of organic compounds and reactions, suggesting that they are relatively unreactive themselves. Indeed, with the exception of the alkanes, cycloalkanes and fluorocarbons, ethers are probably the least reactive, common class of organic compounds.

The inert nature of the ethers relative to the alcohols is undoubtedly due to the absence of the reactive O–H bond.

The most common reaction of ethers is cleavage of the C–O bond by strong acids. This may occur by SN1 or E1 mechanisms for 3º-alkyl groups or by an SN2 mechanism for 1º-alkyl groups.

Some examples are shown in the following diagram. The conjugate acid of the ether is an intermediate in all these reactions, just as conjugate acids were intermediates in certain alcohol reactions.

The first two reactions proceed by a sequence of SN2 steps in which the iodide or bromide anion displaces an alcohol in the first step, and then converts the conjugate acid of that alcohol to an alkyl halide in the second.

Since SN2 reactions are favored at least hindered sites, the methyl group in example #1 is cleaved first. The 2º-alkyl group in example #3 is probably cleaved by an SN2 mechanism, but the SN1 alternative cannot be ruled out. The phenol formed in this reaction does not react further, since SN2, SN1 and E1 reactions do not take place on aromatic rings.

The last example shows the cleavage of a 3º-alkyl group by a strong acid. Acids having poorly nucleophilic conjugate bases are often chosen for this purpose so that E1 products are favored. The reaction shown here (#4) is the reverse of the tert-butyl ether preparation described earlier.

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Epoxides
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The Chemistry of Epoxides

Reactions of Epoxides

Epoxides (oxiranes) are three-membered cyclic ethers that are easily prepared from alkenes by reaction with peracids. Because of the large angle strain in this small ring, epoxides undergo acid and base-catalyzed C–O bond cleavage more easily than do larger ring ethers.

Among the following examples, the first is unexceptional except for the fact that it occurs under milder conditions and more rapidly than other ether cleavages. The second and third examples clearly show the exceptional reactivity of epoxides, since unstrained ethers present in the same reactant or as solvent do not react.

The aqueous acid used to work up the third reaction, following the Grignard reagent cleavage of the ethylene oxide, simply neutralizes the magnesium salt of the alcohol product.


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Sulfur and Phosphorus Compounds
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1. Nucleophilicity of Sulfur Compounds

Sulfur analogs of alcohols are called thiols or mercaptans, and ether analogs are called sulfides. The chemical behavior of thiols and sulfides contrasts with that of alcohols and ethers in some important ways.

Since hydrogen sulfide (H2S) is a much stronger acid than water (by more than ten million fold), we expect, and find, thiols to be stronger acids than equivalent alcohols and phenols. Thiolate conjugate bases are easily formed, and have proven to be excellent nucleophiles in SN2 reactions of alkyl halides and tosylates.

Although the basicity of ethers is roughly a hundred times greater than that of equivalent sulfides, the nucleophilicity of sulfur is much greater than that of oxygen, leading to a number of interesting and useful electrophilic substitutions of sulfur that are not normally observed for oxygen.

Sulfides, for example, react with alkyl halides to give ternary sulfonium salts (equation # 1) in the same manner that 3º-amines are alkylated to quaternary ammonium salts. Although equivalent oxonium salts of ethers are known, they are only prepared under extreme conditions, and are exceptionally reactive.

Remarkably, sulfoxides (equation # 2), sulfinate salts (# 3) and sulfite anion (# 4) also alkylate on sulfur, despite the partial negative formal charge on oxygen and partial positive charge on sulfur.
Phosphorus & Sulfur Ylides

2. Reactions of Ylides

The most important use of ylides in synthesis comes from their reactions with aldehydes and ketones, which are initiated in every case by a covalent bonding of the nucleophilic alpha-carbon to the electrophilic carbonyl carbon.

Alkylidenephosphorane ylides react to give substituted alkenes in a transformation called the Wittig reaction. This reaction is illustrated by the first three equations below. In each case the new carbon-carbon double bond is colored blue, and the oxygen of the carbonyl reactant is transferred to the phosphorus.

The Wittig reaction tolerates epoxides and many other functional groups, as demonstrated by reaction # 1. The carbanionic center may also be substituted, as in reactions # 2 & 3. A principal advantage of alkene synthesis by the Wittig reaction is that the location of the double bond is absolutely fixed, in contrast to the mixtures often produced by alcohol dehydration. With simple substituted ylides Z-alkenes are favored (reaction # 2).

The fourth equation shows a characteristic reaction of a sulfur ylide. Again, the initial carbon-carbon bond is colored blue, but subsequent steps lead to an epoxide product rather than an alkene.

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Aromatic Substitution Reactions
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Substitution Reactions of Benzene and Other Aromatic Compounds

The remarkable stability of the unsaturated hydrocarbon benzene has been discussed in an earlier section. The chemical reactivity of benzene contrasts with that of the alkenes in that substitution reactions occur in preference to addition reactions, as illustrated in the following diagram (some comparable reactions of cyclohexene are shown in the green box).


Many other substitution reactions of benzene have been observed, the five most useful are listed below (chlorination and bromination are the most common halogenation reactions). Since the reagents and conditions employed in these reactions are electrophilic, these reactions are commonly referred to as Electrophilic Aromatic Substitution.

The catalysts and co-reagents serve to generate the strong electrophilic species needed to effect the initial step of the substitution. The specific electrophile believed to function in each type of reaction is listed in the right hand column.

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Amines
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4. Important Reagent Bases

The significance of all these acid-base relationships to practical organic chemistry lies in the need for organic bases of varying strength, as reagents tailored to the requirements of specific reactions.

The common base sodium hydroxide is not soluble in many organic solvents, and is therefore not widely used as a reagent in organic reactions. Most base reagents are alkoxide salts, amines or amide salts.

Since alcohols are much stronger acids than amines, their conjugate bases are weaker than amide bases, and fill the gap in base strength between amines and amide salts. In the following table, pKa again refers to the conjugate acid of the base drawn above it.

Pyridine is commonly used as an acid scavenger in reactions that produce mineral acid co-products. Its basicity and nucleophilicity may be modified by steric hindrance, as in the case of 2,6-dimethylpyridine (pKa=6.7), or resonance stabilization, as in the case of 4-dimethylaminopyridine (pKa=9.7).

Hünig's base is relatively non-nucleophilic (due to steric hindrance), and like DBU is often used as the base in E2 elimination reactions conducted in non-polar solvents. Barton's base is a strong, poorly-nucleophilic, neutral base that serves in cases where electrophilic substitution of DBU or other amine bases is a problem.

The alkoxides are stronger bases that are often used in the corresponding alcohol as solvent, or for greater reactivity in DMSO. Finally, the two amide bases see widespread use in generating enolate bases from carbonyl compounds and other weak carbon acids.

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Aryl Amines
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4. Reaction of Amines with Nitrous Acid

Aryl Amines

Nitrous acid reactions of 1º-aryl amines generate relatively stable diazonium species that serve as intermediates for a variety of aromatic substitution reactions. Diazonium cations may be described by resonance contributors, as in the bracketed formulas shown below.

The left-hand contributor is dominant because it has greater bonding. Loss of nitrogen is slower than in aliphatic 1º-amines because the C-N bond is stronger, and aryl carbocations are comparatively unstable.

Aqueous solutions of these diazonium ions have sufficient stablity at 0º to 10 ºC that they may be used as intermediates in a variety of nucleophilic substitution reactions. For example, if water is the only nucleophile available for reaction, phenols are formed in good yield.

5. Reactions of Aryl Diazonium Salts

Substitution with Loss of Nitrogen

Aryl diazonium salts are important intermediates. They are prepared in cold (0 º to 10 ºC) aqueous solution, and generally react with nucleophiles with loss of nitrogen. Some of the more commonly used substitution reactions are shown in the following diagram.

Since the leaving group (N2) is thermodynamically very stable, these reactions are energetically favored. Those substitution reactions that are catalyzed by cuprous salts are known as Sandmeyer reactions.

Fluoride substitution occurs on treatment with BF4(–), a reaction known as the Schiemann reaction. Stable diazonium tetrafluoroborate salts may be isolated, and on heating these lose nitrogen to give an arylfluoride product.

The top reaction with hypophosphorus acid, H3PO2, is noteworthy because it achieves the reductive removal of an amino (or nitro) group. Unlike the nucleophilic substitution reactions, this reduction probably proceeds by a radical mechanism.

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Reaction of Aldehydes & Ketones
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B. Acetal Formation

Acetals are geminal-diether derivatives of aldehydes or ketones, formed by reaction with two equivalents of an alcohol and elimination of water. Ketone derivatives of this kind were once called ketals, but modern usage has dropped that term.

The following equation shows the overall stoichiometric change in acetal formation, but a dashed arrow is used because this conversion does not occur on simple mixing of the reactants.

In order to achieve effective acetal formation two additional features must be implemented. First, an acid catalyst must be used; and second, the water produced with the acetal must be removed from the reaction. The latter is important, since acetal formation is reversible.

Indeed, once pure acetals are obtained they may be hydrolyzed back to their starting components by treatment with aqueous acid. The mechanism shown here applies to both acetal formation and acetal hydrolysis by the principle of microscopic reversiblity .

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Reaction of Aldehydes & Ketones
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C. Formation of Imines and Related Compounds

The reaction of aldehydes and ketones with ammonia or 1º-amines forms imine derivatives, also known as Schiff bases, (compounds having a C=N function). This reaction plays an important role in the synthesis of 2º-amines, as discussed earlier. Water is eliminated in the reaction, which is acid-catalyzed and reversible in the same sense as acetal formation.

D. Enamine Formation

The previous reactions have all involved reagents of the type: Y–NH2, i.e. reactions with a 1º-amino group. Most aldehydes and ketones also react with 2º-amines to give products known as enamines.

Two examples of these reactions are presented in the following diagram. It should be noted that, like acetal formation, these are acid-catalyzed reversible reactions in which water is lost. Consequently, enamines are easily converted back to their carbonyl precursors by acid-catalyzed hydrolysis.

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Reaction of Aldehydes & Ketones
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2. Irreversible Addition Reactions

The distinction between reversible and irreversible carbonyl addition reactions may be clarified by considering the stability of alcohols having the structure shown below in the shaded box.

If substituent Y is not a hydrogen, an alkyl group or an aryl group, there is a good chance the compound will be unstable (not isolable), and will decompose in the manner shown.

Most hydrates and hemiacetals (Y = OH & OR), for example, are known to decompose spontaneously to the corresponding carbonyl compounds. Aminols (Y = NHR) are intermediates in imine formation, and also revert to their carbonyl precursors if dehydration conditions are not employed.

Likewise, α-haloalcohols (Y = Cl, Br & I) cannot be isolated, since they immediately decompose with the loss of HY. In all these cases addition of H–Y to carbonyl groups is clearly reversible.

If substituent Y is a hydrogen, an alkyl group or an aryl group, the resulting alcohol is a stable compound and does not decompose with loss of hydrogen or hydrocarbons, even on heating.

It follows then, that if nucleophilic reagents corresponding to H:(–), R:(–) or Ar:(–) add to aldehydes and ketones, the alcohol products of such additions will form irreversibly. Free anions of this kind would be extremely strong bases and nucleophiles, but their extraordinary reactivity would make them difficult to prepare and use.

Fortunately, metal derivatives of these alkyl, aryl and hydride moieties are available, and permit their addition to carbonyl compounds.

B. Addition of Organometallic Reagents

The two most commonly used compounds of this kind are alkyl lithium reagents and Grignard reagents. They are prepared from alkyl and aryl halides, as discussed earlier. These reagents are powerful nucleophiles and very strong bases (pKa's of saturated hydrocarbons range from 42 to 50), so they bond readily to carbonyl carbon atoms, giving alkoxide salts of lithium or magnesium.

Because of their ring strain, epoxides undergo many carbonyl-like reactions, as noted previously. Reactions of this kind are among the most important synthetic methods available to chemists, because they permit simple starting compounds to be joined to form more complex structures. Examples are shown in the following diagram.

A common pattern, shown in the shaded box at the top, is observed in all these reactions. The organometallic reagent is a source of a nucleophilic alkyl or aryl group (colored blue), which bonds to the electrophilic carbon of the carbonyl group (colored magenta).

The product of this addition is a metal alkoxide salt, and the alcohol product is generated by weak acid hydrolysis of the salt. The first two examples show that water soluble magnesium or lithium salts are also formed in the hydrolysis, but these are seldom listed among the products, as in the last four reactions.

Ketones react with organometallic reagents to give 3º-alcohols; most aldehydes react to produce 2º-alcohols; and formaldehyde and ethylene oxide react to form 1º-alcohols (examples #5 & 6).

When a chiral center is formed from achiral reactants (examples #1, 3 & 4) the product is always a racemic mixture of enantiomers.

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Reaction of Aldehydes & Ketones
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B. Alkylation Reactions of Enolate Anions

The reaction of alkyl halides with enolate anions presents the same problem of competing SN2 and E2 reaction paths that was encountered earlier in the alkyl halide chapter.

Since enolate anions are very strong bases, they will usually cause elimination when reacted with 2º and 3º-halides. Halides that are incapable of elimination and/or have enhanced SN2 reactivity are the best electrophilic reactants for this purpose.

Four examples of the C-alkylation of enolate anions in synthesis are displayed in the following diagram. The first two employ the versatile strong base LDA, which is the reagent of choice for most intermolecular alkylations of simple carbonyl compounds.

The dichloro alkylating agent used in reaction #1 nicely illustrates the high reactivity of allylic halides and the unreactive nature of vinylic halides in SN2 reactions.

The additive effect of carbonyl groups on alpha-hydrogen acidity is demonstrated by reaction #3. Here the two hydrogen atoms activated by both carbonyl groups are over 1010 times more acidic than the methyl hydrogens on the ends of the carbon chain.

Indeed, they are sufficiently acidic (pKa = 9) to allow complete conversion to the enolate anion in aqueous or alcoholic solutions. As shown (in blue), the negative charge of the enolate anion is delocalized over both oxygen atoms and the central carbon. The oxygens are hydrogen bonded to solvent molecules, so the kinetically favored SN2 reaction occurs at the carbon.

The monoalkylated product shown in the equation still has an acidic hydrogen on the central carbon, and another alkyl group may be attached there by repeating this sequence.

The last example (reaction #4) is an interesting case of intramolecular alkylation of an enolate anion. Since alkylation reactions are irreversible, it is possible to form small highly strained rings if the reactive sites are in close proximity.

Reversible bond-forming reactions, such as the aldol reaction, cannot be used for this purpose. The use of aqueous base in this reaction is also remarkable, in view of the very low enolate anion concentration noted earlier for such systems. It is the rapid intramolecular nature of the alkylation that allows these unfavorable conditions to be used.

The five-carbon chain of the dichloroketone can adopt many conformations, two of which are approximated in the preceding diagram. Although conformer II of the enolate anion could generate a stable five-membered ring by an intramolecular SN2 reaction, assuming proper orientation of the α and γ' carbon atoms, the concentration of this ideally coiled structure will be very low.

On the other hand, conformations in which the α and γ-carbons are properly aligned for three-membered ring formation are much more numerous, the result being that as fast as the enolate base is formed it undergoes rapid and irreversible cyclization.

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Carboxylic Acids
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2. Acidity of Carboxylic Acids

The pKa's of some typical carboxylic acids are listed in the following table. When we compare these values with those of comparable alcohols, such as ethanol (pKa = 16) and 2-methyl-2-propanol (pKa = 19), it is clear that carboxylic acids are stronger acids by over ten powers of ten! Furthermore, electronegative substituents near the carboxyl group act to increase the acidity.

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Carboxylic Acids
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Reactions of Carboxylic Acid Derivatives

1. Acyl Group Substitution

This is probably the single most important reaction of carboxylic acid derivatives. The overall transformation is defined by the following equation, and may be classified either as nucleophilic substitution at an acyl group or as acylation of a nucleophile.

For certain nucleophilic reagents the reaction may assume other names as well. If Nuc-H is water the reaction is often called hydrolysis, if Nuc–H is an alcohol the reaction is called alcoholysis, and for ammonia and amines it is called aminolysis.

Different carboxylic acid derivatives have very different reactivities, acyl chlorides and bromides being the most reactive and amides the least reactive, as noted in the following qualitatively ordered list.

The change in reactivity is dramatic. In homogeneous solvent systems, reaction of acyl chlorides with water occurs rapidly, and does not require heating or catalysts. Amides, on the other hand, react with water only in the presence of strong acid or base catalysts and external heating.

Reactivity: 　 acyl halides > anhydrides >> esters ≈ acids >> amides

Because of these differences, the conversion of one type of acid derivative into another is generally restricted to those outlined in the following diagram.

A better and more general anhydride synthesis can be achieved from acyl chlorides, and amides are easily made from any of the more reactive derivatives. The carboxylic acids themselves are not an essential part of this diagram, although all the derivatives shown can be hydrolyzed to the carboxylic acid state (light blue formulas and reaction arrows). Base catalyzed hydrolysis produces carboxylate salts.

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Carboxylic Acids Derivatives
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Overview of Reducing Agents

The following table summarizes the influence each of the reducing systems discussed above has on the different classes of carboxylic acid derivatives. Note that LAH is the strongest reducing agent listed, and it reduces all the substrates.

In a similar sense, acyl chlorides are the most reactive substrate. They are reduced by all the reagents, but only a few of these provide synthetically useful transformations.

4. Other Reactions

Amides are very polar, thanks to the n-π conjugation of the nitrogen non-bonded electron pair with the carbonyl group. This delocalization substantially reduces the basicity of these compounds (pKa ca. –1) compared with amines (pKa ca. 11).

When electrophiles bond to an amide, they do so at the oxygen atom in preference to the nitrogen. As shown below, the oxygen-bonded conjugate acid is stabilized by resonance charge delocalization; whereas, the nitrogen-bonded analog is not.

One practical application of this behavior lies in the dehydration of 1º-amides to nitriles by treatment with thionyl chloride. This reaction is also illustrated in the following diagram. Other dehydrating agents such as P2O5 effect the same transformation.

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Reactions at the α-Carbon
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Reactions at the α-Carbon

1. Enolate Intermediates

Many of the most useful alpha-substitution reactions of ketones proceeded by way of enolate anion conjugate bases. Since simple ketones are weaker acids than water, their enolate anions are necessarily prepared by reaction with exceptionally strong bases in non-hydroxylic solvents.

Esters and nitriles are even weaker alpha-carbon acids than ketones (by over ten thousand times), nevertheless their enolate anions may be prepared and used in a similar fashion.

The presence of additional activating carbonyl functions increases the acidity of the alpha-hydrogens substantially, so that less stringent conditions may be used for enolate anion formation. The influence of various carbonyl and related functional groups on the equilibrium acidity of alpha-hydrogen atoms (colored red) is summarized in the following table.

For common reference, these acidity values have all been extrapolated to water solution, even though the conjugate bases of those compounds having pKas greater than 18 will not have a significant concentration in water solution.

Acidity of α-Hydrogens in Mono- and Di-Activated Compounds

To illustrate the general nucleophilic reactivity of di-activated enolate anions, two examples of SN2 alkylation reactions are shown below. Malonic acid esters and acetoacetic acid esters are commonly used starting materials, and their usefulness in synthesis will be demonstrated later in this chapter.

Note that each of these compounds has two acidic alpha-hydrogen atoms (colored red). In the equations written here only one of these hydrogens is substituted; however, the second is also acidic and a second alkyl substitution may be carried out in a similar fashion.



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Heterocyclic Chemistry
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Heterocyclic Compounds

Compounds classified as heterocyclic probably constitute the largest and most varied family of organic compounds. After all, every carbocyclic compound, regardless of structure and functionality, may in principle be converted into a collection of heterocyclic analogs by replacing one or more of the ring carbon atoms with a different element.

Even if we restrict our consideration to oxygen, nitrogen and sulfur (the most common heterocyclic elements), the permutations and combinations of such a replacement are numerous.

Nomenclature

Devising a systematic nomenclature system for heterocyclic compounds presented a formidable challenge, which has not been uniformly concluded. Many heterocycles, especially amines, were identified early on, and received trivial names which are still preferred.

Some monocyclic compounds of this kind are shown in the following chart, with the common (trivial) name in bold and a systematic name based on the Hantzsch-Widman system given beneath it in blue. The rules for using this system will be given later. For most students, learning these common names will provide an adequate nomenclature background.

An easy to remember, but limited, nomenclature system makes use of an elemental prefix for the heteroatom followed by the appropriate carbocyclic name. A short list of some common prefixes is given in the following table, priority order increasing from right to left.

Examples of this nomenclature are: ethylene oxide = oxacyclopropane, furan = oxacyclopenta-2,4-diene, pyridine = azabenzene, and morpholine = 1-oxa-4-azacyclohexane.

The Hantzsch-Widman system provides a more systematic method of naming heterocyclic compounds that is not dependent on prior carbocyclic names. It makes use of the same hetero atom prefix defined above (dropping the final "a"), followed by a suffix designating ring size and saturation.

As outlined in the following table, each suffix consists of a ring size root (blue) and an ending intended to designate the degree of unsaturation in the ring. In this respect, it is important to recognize that the saturated suffix applies only to completely saturated ring systems, and the unsaturated suffix applies to rings incorporating the maximum number of non-cumulated double bonds.

Systems having a lesser degree of unsaturation require an appropriate prefix, such as "dihydro"or "tetrahydro".

Despite the general systematic structure of the Hantzsch-Widman system, several exceptions and modifications have been incorporated to accomodate conflicts with prior usage.

Examples of these nomenclature rules are written in blue, both in the previous diagram and that shown below. Note that when a maximally unsaturated ring includes a saturated atom, its location may be designated by a "#H " prefix to avoid ambiguity, as in pyran and pyrrole above and several examples below.

When numbering a ring with more than one heteroatom, the highest priority atom is #1 and continues in the direction that gives the next priority atom the lowest number.

All the previous examples have been monocyclic compounds. Polycyclic compounds incorporating one or more heterocyclic rings are well known. A few of these are shown in the following diagram.

As before, common names are in black and systematic names in blue. The two quinolines illustrate another nuance of hetrocyclic nomenclature.

Thus, the location of a fused ring may be indicated by a lowercase letter which designates the edge of the heterocyclic ring involved in the fusion, as shown by the pyridine ring in the green shaded box.

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ラボ会話

　英語が得意のつもりでも、いざ海外に出て行くと思うように会話ができないことが多い。これは語彙の不足にもよるだろうが、日本の英語教育で読み書きのみを偏重した結果、正しい発音を知らないためである。ここでは、米国の有機化学研究室に留学した場面を想定して、どのような会話が実際になされるかを疑似体験し、耳をならしていただきたい。

1. Finding an Article in a Library （図書館で文献を探す）
2. Ordering a Chemical （試薬の注文）
3. Solvent Disposal （溶媒の廃棄）
4. Making a Lithium Diisopropylamide （LDAの調製）
5. In the Professor's Office （教授室での会話）
6. In the Laboratory （実験室での会話）
7. Searching for Chemicals （試薬探し）
8. Ozonolysis （オゾン分解）
9. After the Reaction （実験を終えて）
Dialogue 1: Finding an Article in a Library


会話を開始する
A: Can I ask you a question? How can I get this article?
B: Sure, let's see . . .
A: I tried several times to download the pdf file from the web, but I couldn't find the article.
B: Ah, I don't think the publisher has articles before 1972 on the web yet. You'll have to go to the library to get the article. I know our university subscribes to the paper version of this journal, so it should be there. Have you been to the science library yet?
A: Yes, but just to look around. I have no idea how to find this article.
B: Recent articles are kept on the first floor for a couple of months before they are moved into the stacks. This is an older one so you'll have to go to either the third or fourth floor to find this journal, I don't remember which. All the journals are grouped by subject, like chemistry, biology, physics etc, and then alphabetically. Look at the floor directory near the stair case to see where the journal is shelved. Don't worry, it might take some time, because even after doing this for a while, I still have a hard time finding some journals.
A: Alright, so I can check the journal out with my library card and copy what ever pages I need with our copier in the office?
B: No, journals and reference material are non-circulating, so they can't be checked out of the library. That's so everyone can have access to the journal any time the library is open. There's a copy machine on each floor so you can just use our group copy card to make your copies. The card is hanging in the office.
A: Thanks.
B: No problem.

会話インデックスに戻る


会話１： 図書館で文献を探す

A: ちょっと聞いていいですか？この論文はどうしたら手に入りますか？
B: ええと、そうだね…
A: 何回か出版社のサイトからpdfファイルをダウンロードしてみようと思ったのですけど見つからなかったんです。
B: そう、1972年以前のものについてはまだ出版社のサイトには載っていないと思うよ。この論文が欲しいのなら図書館に行かないとだめだね。ここの図書館はこの論文の冊子を購読しているからあると思う。科学系の図書館には行ったことありますか？
A: はい、でもただ見て回っただけです。この論文をどう探せばいいのかは全然分からないです。
B: 最近の文献は何ヶ月か一階に置かれた後で書架に入れられるんだ。あなたの探している論文は古いものだから三階か四階、どちらだったかの書庫に行って探さないといけないね。文献は化学、生物、物理のように分野ごとにわけられていて、その中でさらにアルファベットごとに並べられているよ。階段踊り場近くの案内板でどこに文献がおさめられているか見るといいよ。最初は少し時間がかかるかもしれないけど、心配はいらないよ。なにせ僕ももうけっこう長いことやっているけどいまだに文献を探すのにはときどき苦労するからね。
A: 分かりました、私の図書館カードを使ってその文献を借りてきて、オフィスでほしいページをコピーすればいいのですね。
B: いえ、論文や文献は貸し出しできないんだ。というのも、そうすることで図書館があいているときにはいつでも論文が読めるようになっているのでね。コピー機は各階にあるからうちのグループ用カードを使って向こうでコピーができるよ。カードはオフィスにぶら下がっているから。
A: ありがとう。
B: いえ。
会話インデックスに戻る

Dialogue 2: Ordering a Chemical


会話を開始する
A: I need some triphenylphosphine, and all I found was this bottle that's almost empty. I need more than what's in here for my Mitsunobu reaction. What should I do?
B: How much do you need?
A: Lots. And, uh . . . right now.
B: Well, for future reference, you should have checked earlier. Have you asked around to see if someone in our group has a private stash, otherwise you'll have to borrow some from another group?
A: Yeah, no one in our group has any, but I'll go ask the Smith group for some, I know they use a lot of it for Wittig reactions, and I return the amount when our new bottle comes in.
B: That sounds fine, but let's place an order today so the next person that needs it will have some.
A: And how do you do that.
B: These are the order forms we use to get our chemicals. Look through these catalogs to see which company has the best price, then fill out the description, catalog number, amount, price, etc. and then take it to the secretary that places all our orders. You better hurry, because I think he'll place today's order in the next ten minutes or so.
A: What size should I order?
B: We go through a lot of triphenylphosphine, and it doesn't oxidize that easily, so order 500 grams.
A: Alright, thanks for your help.
会話インデックスに戻る
会話２： 試薬の注文

A: トリフェニルフォスフィンが必要なんですが、ほとんど空になってるこの瓶しか見つかりませんでした。光延反応をするのにこの瓶の中にあるよりも量が必要なんです。どうしたらいいですか？
B: どのくらい必要なの？
A: たくさんです…しかも、えーと今すぐなんです。
B: そうか、先にやる予定のことは早めに準備しておかなくてはだめだよ。ラボの誰かが個人持ちしてないか聞いて回ってみた？なければ他のラボから借りることになるね。
A: ええ、うちでは誰も持ってませんでした。でもスミス研に行って借りてきます。あそこではウィッティヒ反応にたくさん使ってますから。それで新しい瓶が来たら返します。
B: これが試薬の注文票だよ。ここにあるカタログから一番安いものを探して化合物名とカタログ番号、量、値段などを書いて係のところに持っていってね。彼が注文をしてくれるよ。急いだ方がいいよ、彼はあと10分かそこらで今日の注文をするはずだから。
A: どのサイズを注文したらいいですか？
B: トリフェニルフォスフィンはたくさん使うしそれほど簡単に酸化されるわけでもないので500グラムを注文してね。
A: 分かりました。どうもありがとうございます。
会話インデックスに戻る

Dialogue 3: Solvent Disposal


会話を開始する
A: I just rotovapped off quite a bit of methylene chloride. Which waste container should I use?
B: All waste containing halogenated solvents like dichloromethane and chloroform go into the brown container-even if it's just a minor fraction of the solvent.
A: And the other two tanks are for non-halogenated waste?
B: Yup, the smaller white container is for non-halogenated solvents like hexanes, ethyl acetate, and such, and the larger container is for aqueous waste containing organics. You should try your best at separating the three types of waste, and please don't throw any aqueous waste down the sink.
A: Why do we have to waste our time separating the different wastes? Don't they all get burned together?
B: Yes, but they burn at different rates and give off different types of byproducts after combustion. In order to maximize the burning efficiency, to ensure safety of the workers and the incinerator, and to protect the air we breathe, we should do our best to separate the different solvent types.
A: OK, OK, good point, now I understand. I'll try my best to empty the rotovap trap between different solvent classes. Thanks for the help.
B: You're welcome. By the way, I noticed you have unlabeled containers in the back of your hood. You should make sure everything has a descriptive label before you forget what was inside. It's very expensive to get rid of unknown waste.
A: Oh, sorry, I'll do it right now.
会話インデックスに戻る


会話３： 溶媒の廃棄

A: メチレンクロライドを少しエバポしたんですけど、どの廃液入れに入れればいいですか？
B: ジクロロメタンやクロロホルムみたいにハロゲンを含んだ溶媒は少し含んでいるだけでも茶色のポリタンクに入れてね。
A: じゃあ他の二つのポリタンクはハロゲンを含んでいないもの用ですか？
B: そう、小さい方の白いタンクはハロゲンを含んでいないヘキサンや酢酸エチルなどを入れるもので、大きい方は有機化合物を含んだ水系の廃液用だよ。この三種類の廃液は最大限努力して分けるようにしてね。あと水系の廃液を流しには捨てないこと。
A: どうしてわざわざ種類を分けないといけないんですか？一緒にまぜて燃やすのではないのですか？
B: そう、でもそれぞれ燃え易さも違うしそれぞれ燃やした後に出る廃棄物の種類も違うんだよ。燃焼の効率を最もよくして、作業員と燃焼炉の安全を確保し、私たちの吸っているこの空気をきれいにするためにもできる限り溶媒の種類は分けないといけないんだ。
A: そうだね、うん、そのとおりだよ。もう大丈夫です。溶媒の種類を変えるときにはトラップを空にするようにします。いろいろありがとう。
B: いえいえ。ところで、君のドラフトの奥になにもシールが貼られてない容器があるね。中に何が入っているか忘れてしまう前にすべての容器には説明書きを書いておかないとだめだよ。中味の分からない廃液を処理してもらうのはとてもお金がかかるんだ。
A: あぁ、ごめんなさい。今すぐやります。
会話インデックスに戻る

Dialogue 4: Making Lithium Diisopropylamide


会話を 開始する
A: Hey, I need to make about 10 mmol of LDA for my next reaction. What is the best way to do it?
B: Did you find an appropriate experimental procedure for your reaction?
A: Yes, but there are no details on how the LDA solution was made, just that a solution of LDA was used, etc. The protocol to make the LDA was not written in the experimental.
B: OK, here's the gist of it. You have to use very dry glassware because the reaction is moisture sensitive and moisture will affect the quality of your reaction. Take a solution of 10.5 mmol diisopropylamine in 50 mL anhydrous THF and cool to zero degrees. Slowly add 10 mmol of n-butyllithium solution at 0 degrees and let stir for about 30 minutes, this should be ample time for complete deprotonation. That's it, then you have 10 mmols LDA in your flask. Be careful when disposing of any excess n-butyllithium that remains in the syringe.
A: Why is that? Is it dangerous to use? I've never used it before, so I'm not sure how to do it correctly.
B: In that case, I'll walk you through it the first time. In the beginning it's probably a good idea to ask for help when using a reagent or running a reaction that could be potentially dangerous. Until you are comfortable running the reaction on your own, just ask around if to see if anyone has experience with what ever chemistry you are doing.
A: Great, I really appreciate it.
B: Don't mention it. Here, let's use this bottle of n-butyllithium, I titrated it this morning.
会話インデックスに戻る


会話４： LDAの調製

A: ねぇ、次の反応に10 mmolのLDAが必要なんだけどどうするのが一番いいですか？
B: その反応のちゃんとした実験項はあるのかい？
A: はい、でもLDAをどうやって作ったかについては書いてなくて、ただLDAの溶液を使った、みたいに書いてあるんです。実験項にはLDAの作り方は書いてなかったです。
B: じゃあ要領だけ説明するよ。ガラス器具はできるだけ乾燥させておいてね。この反応は水に影響を受けやすいし水のせいで反応のがきれいにいかないこともあるんだ。10.5 mmolのジイソプロピルアミンを50 mLのTHFに溶かして0℃に冷却。10 mmolのn-ブチルリチウム溶液を0℃でゆっくり加えて30分撹拌。この程度の時間をかければ脱プロトン化するには十分だよ。これで10 mmolのLDAができる。シリンジに残ったn-ブチルリチウムを捨てるときには気をつけてね。
A: なんでですか？危険なんでしょうか？使ったことがないのでどうやったらいいのかよくわかりません。
B: それなら、今回は一緒にいてみてあげるよ。はじめのうちは危険な試薬を使ったり危険な反応を行ったりするときには手助けしてもらった方がいいよ。一人で問題なく反応が行えると思うまでは自分がやっている反応の経験がある人を探してみた方がいいよ。
A: ありがとう、恩に着ます。
B: いや、当たりまえのことですよ。じゃあこのn-ブチルリチウムを使っていいよ。今朝滴定したばかりだから。
会話インデックスに戻る

Dialogue 5: In the Professor's Office


会話を開始する
A: Hello, my name is Koichi Isobe, I have just arrived from Japan. It's nice to meet you.
B: Ah yes, please, come in, sit down. I've been looking forward to your arrival. I have some interesting ideas for your research project. It will definitely be challenging, so I hope you're up for it.
A: Oh, thank you very much, I'll try my best. Oh, this is a gift for you from Japan.
B: Ah, thank you. What is it?
A: It is uirou, a famous Japanese sweet, and it comes from my hometown.
B: Looks good. Well, I have a meeting in a few minutes, but afterward why don't we go grab a coffee so we can start discussing your research and we can try the uirou then. I'll walk you over to our labs so you can meet the group, and they can help you get set up at your bench.
A: Sounds great!
会話インデックスに戻る


会話５： 教授室にて

A: 失礼します。はじめまして、イソベコウイチです。日本からただいま到着致しました。
B: どうぞ、お座りください。あなたが来ることを（首を長くして）待っていたよ。あなたのプロジェクトに、いいアイデアがあるんだ。かなりやりがいのあるプロジェクトだから、やり遂げてくれると期待しているよ。
A: ありがとうございます。全力を尽くしてがんばります。ところで、こちらは日本からのお土産です。
B: ありがとう。何かな？
A: 「ういろう」です。日本の有名なお菓子で、故郷の名産品なんです。
B: おいしそうだね。このあと会議があるんだけど、それが終わったら、コーヒーでも飲みながら、これからの研究についてディスカッションしようじゃないか。そのときういろうを一緒にいただこう。それじゃ、実験室まで案内するよ。グループのメンバーがいるから、実験台の立ち上げを手伝ってもらってください。
A: よろしくお願い致します。
会話インデックスに戻る

Dialogue 6: In the Laboratory


会話を開始する
A: Hello, my name is Koichi Isobe, nice to meet you. I'm the new student from Japan.
B: Hi Koichi, I'm John, a third year graduate student, nice to meet you. We've been expecting you, so I'm glad you've arrived safely. We'll both be working in this area . . . here's your bench . . . and we'll share this hood. This is your desk, and that's mine. Hopefully everything is up to standard.
A: Yes, looks very nice. By the way, how should we address the professor?
B: Most people call him by his first name, Ben, but you can call him Professor or Doctor Franklin too if you want, he doesn't mind.
A: You call the professor by his first name?
B: Yes, it's fairly informal here, and it is often by the professor's request. Let's go meet the rest of the group and I'll show you the rest of the labs.
会話インデックスに戻る

会話６： 実験室にて

A: こんにちは。イソベコウイチと申します。初めまして。日本から来ました新入生です。
B: こんにちは、コウイチ。僕はジョン、３年生です。よろしく。あなたのことを楽しみにしていたよ。無事到着して何よりだ。僕たちはこの場所で一緒に仕事をすることになるけど、ここがあなたのベンチ、そしてこのドラフトは一緒に使いましょう。こちらがあなたの机、でここが僕。まあ平均的な感じだと思うけど。
A: すばらしいですね。ところで、皆さんは教授のことをどのように呼んでいるんですか？
B: ほとんどは彼の名前「ベン」ってよんでいるよ。ただ「教授」や「フランクリン博士」と呼びたいのなら、彼は気にしないけどね。
A: ジョンはやはり名前で呼んでいるのですか？
B: もちろん。ここはそんな堅苦しくないし、それに教授の要望でもあるんだ。さあ、ラボの他の人たちに会いに行こう。案内してあげるよ。
会話インデックスに戻る

Dialogue 7: Searching for Chemicals


会話を開始する
A: John, sorry to bug you again, but I need to use Meldrum's acid. Where is it located?
B: I wonder if we have Meldrum's acid. Let's check the computer. All the chemicals in our laboratory are registered on a spreadsheet so we can quickly search if and where a particular chemical would be. Go ahead and try it, it's pretty simple to use.
A: Let's see . . . ah, here it is! According to this, it should be in the carboxylic acid and derivatives cabinet. Where is that?
B: It's two rooms down, on this side of the hall. All the cabinets have labels on the doors describing what category of chemical is stored inside. All the chemicals are arranged according to the number of carbons within a category.
A: Ok, I'll go look for it. Do I have to sign it out or anything?
B: Uh, sorry, yes, I forgot to mention that. There is a clipboard hanging next to the cabinet. Fill in the information for each chemical that you remove from storage. And if you can't find the chemical, check the clip board to see if someone has already taken it out. Good luck.
A: Thanks.
会話インデックスに戻る


会話７： 試薬探し

A: ジョン、また邪魔してごめん、メルドラム酸を使いたいんだけどどこにあるんだい？
B: メルドラム酸はあったかな。パソコンで調べてみよう。うちのラボにある化合物は全部表計算ソフトに登録してあるからあるかどうかとかどこにあるかとかすぐに検索できるんだ。ちょっといってやってみよう、とっても簡単だよ。
A: そうだね…あ、あるみたいだよ。これによるとカルボン酸誘導体の棚にあるみたいだけど、これはどこにあるの？
B: 廊下のこちら側の二つとなりの部屋にあるよ。棚には表にラベルが張ってあってどんな種類の化合物が入ってるか書いてあるよ。その種類ごとに分けられた上、化合物はさらに炭素数ごとに分けられているんだ。
A: オーケー、じゃあ行って見てみるよ。持っていくときには何か書いたりとかしないといけないの？
B: んー、ごめん、言い忘れてたよ。棚の横にはクリップボードがかかってるんだ。取り出した化合物の情報を書き込んでね。化合物が見つからないときはクリップボードを見て誰か持っていってないか確認してよ。じゃあ。
A: ありがとう。
会話インデックスに戻る

Dialogue 8: Ozonolysis


会話を開始する
A: I want to use the ozone generator. Could you please show me how to use it?
B: No problem. But, I'm in the middle of a column right now, how about in fifteen minutes?
A: Ah, sounds good. That will give me time to prepare my substrate. I'll come back in fifteen minutes.
B: OK, what's the substrate and how much are you going to use?
A: This is my substrate, and immediately after ozonolysis I want to reduce the resulting aldehyde to the alcohol with sodium borohydride. I have about a gram in here.

B: That sounds reasonable. Make a solution in methanol and cool it to negative 78 with dry ice/acetone and then put it on this stir plate. Here's a Dewar you can use.
A: Ok, I'm ready. Why was methanol chosen as a solvent?
B: The reaction is usually cleaner if it's run in methanol, there are fewer side reactions. So, this is the ozone generator. First thing to do is to turn on the water for the cooling coils. It doesn't have to be gushing out, just enough to dissipate the heat.
A: Uh, how's that?
B: Good enough. Here is the outlet for the ozone/oxygen mixture. Immerse the tip of the outlet into the clamped test tube. I just fill it with regular methanol. Now we can open the oxygen tank slowly, and adjust the flow by looking at the bubbles coming from the outlet.
A: And, how's that?
B: That's good. Now, turn on the generator. Here's the switch.
A: OK.
B: Let's check whether there's a sufficient amount of ozone being generated. Stretch a rubber band on top of the test tube.
A: Wow! It was chewed in half.
B: Yes, the double bonds in the isoprene chains were oxidized and cleaved. Let's start the reaction. Place the tip of the outlet into your reaction. Be careful not to get the ozone on your skin or breathe it, since it is very toxic.
会話インデックスに戻る


会話８： オゾン分解

A: オゾン発生装置を使いたいのですが、教えてもらえますか？
B: いいよ。でもいまカラムの最中だから、１５分くらい待ってもらえるかな？
A: わかりました。準備をするのに丁度良いです。１５分くらいしたらまた来ますね。
B: さあおまたせ。どんな基質で、どれくらいの量使う予定だい？
A: これです。オゾン分解の後、水素化ホウ素ナトリウム（ソジボロ）ですぐにアルデヒドをアルコールまで還元したいと思います。いま１グラムくらい持っています。
B: 大丈夫そうだね。それではメタノールに溶かして、ドライアイス-アセトンで-７８度に冷やして、スターラーの上に設置してください。ここにデュワーが有るから、使っていいよ。
A: ありがとうございます。どうして反応溶媒にメタノールを使うのですか？
B: メタノールを使った方が、副反応が抑えられて、反応がきれいにいくことが多いね。さて、これがオゾン発生装置だよ。まず冷却水を流してください。そんなにじゃぶじゃぶ流す必要はなくて、冷却に必要なだけ流れていればいいよ。
A: これくらいでどうですか？
B: いいね。ここからオゾンが出てくるんだ。その先端を固定した試験管に入れて、試験管にメタノールを入れて。それから酸素ボンベをゆっくりと開けるんだけど、出口からの泡の出方を見て、流量を調節するんだ。
A: これくらいですか？
B: そうそう。それでは装置のスイッチを入れよう。これがスイッチだ。
A: わかりました。
B: それではオゾンが発生しているか確認してみよう。輪ゴムを試験管の上でのばしてごらん。
A: おお、半分にちぎれましたね。
B: イソプレン鎖の二重結合が酸化されて切れたんだよ。それでは反応を始めよう。それでは出口の先端を反応容器の中に入れよう。毒性が強いから、肌に触れたり吸い込んだりしないように注意してね。
会話インデックスに戻る

Dialogue 9: After the Reaction


会話を開始する
B: So, how's it going? Did you get the alcohol?
A: From the proton NMR, it looks like one of the methoxy groups has disappeared.
B: May I see it? There's a singlet at about 5.5 ppm, so there is an acetal. Oh, it looks like the methylene protons next to the oxygen are separated. I think you may have generated the cyclic ketal.
A: What? How did that happen?
B: Well, if there was any trace acid during the work up, the acid may have catalyzed the hydroxyl displacement of one of the methoxy groups from the acetal.
A: Can I prevent the cyclization from occurring and get the benzylic alcohol?
B: I think if you add triethylamine to the reaction mixture after the reduction, it should prevent cyclization during work up.
A: OK, I'll try that next time. Thanks for your help.
会話インデックスに戻る


会話９： 実験を終えて

B: どうだい。アルコールは取れた？
A: それが、NMRを見るとメトキシ基が一つどこかにいってしまったようなんです。
B: ちょっと見せてもらっていいかな？5.5 ppmにシングレットが一つあるね。ということはアセタールがあるのかな。酸素の隣のメチレンプロトンが非等価に出ているね。巻き込んでアセタールになってしまったんじゃないかな（環状アセタールができているんじゃないかな）？
A: え、どういうことですか？
B: 後処理の段階でちょっとでも酸があると、その酸が触媒になってメトキシ基と水酸基の交換を起こしてしまったんじゃないかな。
A: その環化を防いで、ベンジルアルコール体を取ることはできないですか？
B: 還元の後で、トリエチルアミンを加えてみてはどうかな。後処理での環化を防いでくれると思うよ。
A: わかりました。試してみます。どうもありがとうございます。
会話インデックスに戻る

実験用具など

recovery flask
ナスフラスコ

pear shaped flask
ナシフラスコ

three-necked round-bottom flask
三口フラスコ（丸底）

test tube
試験管

culture tube
screw-top test tube
培養管
ねじ口試験管

beaker
ビーカー

Erlenmeyer flask
三角フラスコ

rubber septum
(複数形：septa)
セプタム

cork
stopper
コルク栓

glass stopper
ガラス栓

glass syringe
（ガラス製）注射器

plastic syringe
注射器

syringe needle
注射針

microsyringe
マイクロシリンジ

syringe pump
シリンジポンプ

clamp
クランプ
クランメル

ring support
（カット）リング

balloon
風船

　drying tube
塩化カルシウム管
塩カル管

Vigreux column
Vigreuxカラム

vacuum filtration adapter
減圧ろ過用アダプター

reducing adapter & enlarging adapter
径違い管
ジョイント

atomizer bulb
（霧吹き用）ゴム単球

TLC plate
TLCプレート

diamond glass cutter
ダイアモンドガラスカッター

UV lamp
UVランプ

glass capillaries
キャピラリー

TLC developing chamber
TLC展開槽

ampule cutter
glass scorer
glass scoring stone
米国にはなく、Emory cloth
という布やすりで代用

ampule (ampoule)
アンプル

hot plate
ホットプレート

evacuation flask
スリ付き試験管

spatula
スパーテル

vial
バイアル

micro vial
ミクロチューブ

Parafilm®
パラフィルム

cotton
脱脂綿

graduated cylinder
メスシリンダー

pipet bulb
ピペット用スポイト

pipet (pipette)
ピペット

Pasteur pipet
パスツールピペット

magnetic stirrer
stir plate
マグネチックスターラー

magnetic stir bar retriever
攪拌子取り出し棒

vortex stirrer
ボルテックス

mortar and pestle
乳鉢と乳棒

glass funnel
ガラスロート

vacuum adapter
連結管（吸引付き）

Dean-Stark trap
Dean-Starkトラップ

fritted gas dispersion tube
木下式ガラスボールフィルター

chromatographic column with filter disc
クロマト用カラム

sintered glass funnel
グラスフィルター

Hirsch funnel
桐山ロート

Buchner funnel
ブフナーロート

filter paper
濾紙

neoprene filter adapter
ゴムアダプター

filter flask
吸引ビン

rubber hose
ゴムホース

Dewar condenser
Dewar冷却管

Dewar
Dewar flask
デュワー

cannula
カニュラ

dry ice
ドライアイス

mallet
木づち

Kugelrohr distillation oven
クーゲルロール蒸留装置

analytical balance
電子分析天秤

top loading balance
電子はかり

weighing paper
薬包紙

rotary evaporator (rotovap)
エバポレーター

water bath
湯浴

heating mantle
マントルヒーター

thermocouple thermometer
熱電対温度計

oil bath
油浴

heat gun
ヒートガン

melting point apparatus
融点測定器

safety glasses
保護メガネ

silica gel for drying
乾燥用シリカゲル

petri dish
ペトリ皿

sea sand
海砂

molecular sieves
モレキュラーシーブス

cork ring
コルベン台

rubber flask stand
コルベン台

pH paper
pH試験紙

Latex gloves
ゴム手袋

metal clip, and Keck clip
ジョイントクリップ

lab coat
白衣

wash bottle
洗（浄）瓶

squeeze-bulb pump
灯油ポンプ

lab jack
ジャッキ

aluminum foil
アルミフォイル

mask
防塵マスク

reagent bottle
試薬瓶

cap
フタ

vacuum pump
真空ポンプ

vacuum manifold
マニフォルド

vacuum gauge
マノメーター

vacuum grease (silicone grease)
真空グリース

gas bubbler
bubbler
バブラー

Teflon tape
テフロンテープ

Schlenk flask
Schlenkフラスコ

Schlenk tube
Schlenkチューブ

vacuum trap
トラップ

diaphragm pump
ダイアフラムポンプ

bench
実験台

desiccator
デシケーター

liquid chromatograph (LC)
液体クロマト（液クロ）

centrifuge
遠心分離器

drying oven
乾燥機

safety shield
シールド

drying rack
ドライボード

fume hood
ドラフト

gas cylinder
ガスボンベ

fire extinguisher
消火器

lattice support
monkey bars
ジャングル

gas lighter
ガスライター

(glass blowing) torch
ガスバーナー

explosion-proof freezer
（防爆）フリーザー

ultrasonic bath
sonicator
超音波洗浄器

lab stool
回転イス

applicator stick
wooden stick
（applicator stickは先端が尖っていなかった）
竹串

labels
ラベル

toilet paper
トイレットペーパー

stopwatch
ストップウオッチ

molecular model
分子模型

thermometer-hygrometer
温度計・湿度計

brush
ブラシ

NMR tube
NMRサンプル管

mass spectrometer (mass spec)
質量分析計（マス）

FTIR spectrometer
赤外分光光度計（ＩＲ）

X-ray diffractometer
X-線回折装置

polarimeter
旋光計

whiteboard
ホワイトボード

marker
マーカー

eraser
（白板）消し

wrench
レンチ

file
やすり

Philips head screwdriver
プラスードライバー

flat head screwdriver
（普通の）ドライバー

Kimwipes®
キムワイプ

Band-Aid®
バンドエイド

magnet
磁石

calculator
計算機

eraser
消しゴム

tape dispenser
テープディスペンサー

glue stick
スティックのり
"" width="220"

box cutter
razor blade
カッター

stapler
ホッチキス

2-hole punch
paper puncher
２穴パンチ

rubber band
輪ゴム

microwave oven
電子レンジ

sink
流し

magazine rack
雑誌棚

bookshelf
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（主として現代の）有機化学者名


　外国の先生の名前を正しく発音できない、ということを時々耳にする。ここでは主として米国の有機合成化学者の名前を独断と偏見を持って並べてみた。実際、本人に聞いてみないと、どのような発音が正しいのかアメリカ人でも分からないことがままある。また、英語圏外の化学者の名前も、その国での発音を使う場合と、英語読みに直して発音する場合もあるので、ここでは、一般に米国でどんな呼び方をしているかという参考程度に頭に入れておけばよいと思う。
姓、名
名、姓
所属
Aggarwal, Varinder Varinder Aggarwal Univ. of Bristol
Aubé, Jeffrey Jeffrey Aubé (Jeff)　 Univ. of Kansas
Bach, Thorsten Thorsten Bach　 Tech. Univ. of München
Baldwin, Jack Jack Baldwin retired (Oxford Univ.)
Baran, Phil Phil Baran 　 The Scripps Institute
Barrett, Anthony Anthony Barrett (Tony) Imperial College London
Barton, Derek Derek Barton deceased (Texas A&M Univ.)
Barton, Jacqueline Jacqueline Barton Caltech
Beak, Peter Peter Beak Univ. of Illinois at Urbana-Champaign
Bertozzi, Carolyn Carolyn Bertozzi Univ. of California, Berkeley
Boeckman, Robert Robert Boeckman (Bob) Univ. of Rochester
Boger, Dale Dale Boger　 The Scripps Institute
Bolm, Carsten Carsten Bolm R-W. Hochschule Aachen
Breslow, Ronald Ronald Breslow (Ron) Columbia Univ.
Brimble, Margaret Margaret Brimble Univ. of Auckland
Brown, Herbert C. Herbert C. Brown (HC) deceased (Purdue Univ.)
Büchi, George George Büchi　 deceased (MIT)
Buchwald, Stephen Stephen Buchwald (Steve)　 MIT
Carreira, Erick Erick Carreira ETH
Charette, Andre Andre Charette Univ. of Montreal
Ciufolini, Marco Marco Ciufolini　 Univ. of British Columbia
Clardy, Jon Jon Clardy Harvard Univ.
Comins, Daniel Daniel Comins (Dan) North Carolina State Univ.
Cook, James James Cook (Jim)　 Univ. of Wisconsin, Milwaukee
Corey, Elias J. Elias J. Corey (EJ)　 Harvard Univ.
Cossy, Janine Janine Cossy ESPCI (Paris)
Cram, Donald Donald Cram (Don) deceased (UCLA)
Crimmins, Michael Michael Crimmins (Mike) Univ. of North Carolina
Curran, Dennis Dennis Curran Univ. of Pittsburgh
Danheiser, Rick Rick Danheiser　 MIT
Danishefsky, Samuel Samuel Danishefsky (Sam) Sloan-Kettering Institute
Davies, Huw Huw Davies SUNY, Buffalo
Davis, Franklin Franklin Davis Temple Univ.
Denmark, Scott Scott Denmark Univ. of Illinois at Urbana-Champaign
Dervan, Peter Peter Dervan Caltech
DeShong, Philip Philip DeShong (Phil) Univ. of Maryland
Doyle, Michael Michael Doyle (Mike) Univ. of Maryland
Du Bois, Justin Justin Du Bois　 Stanford Univ.
Ellman, Jonathan Jonathan Ellman (Jon) Univ. of California, Berkeley
Enders, Dieter Dieter Enders R-W. Hochschule Aachen
Eschenmoser, Albert Albert Eschenmoser The Scripps Institute (ETH)
Evans, Andrew Andrew Evans (Andy) Univ. of Indiana
Evans, David David Evans (Dave) Harvard Univ.
Fleming, Ian Ian Fleming retired (Cambridge Univ.)
Forsyth, Craig Craig Forsyth Univ. of Minnesota
Fu, Gregory Gregory Fu (Greg) MIT
Fuchs, Philip Philip Fuchs (Phil) Purdue Univ.
Fürstner, Alois Alois Fürstner　 Max Planck Institute
Funk, Raymond Raymond Funk (Ray) Pennsylvania State Univ.
Gallagher, Timothy Timothy Gallagher (Tim) Univ. of Bristol
Garner, Philip Philip Garner (Phil) Case Western Reserve Univ.
Gellman, Samuel Samuel Gellman (Sam) Univ. of Wisconsin, Madison
Gevorgyan, Vladimir Vladimir Gevorgyan Univ. of Illinois at Chicago
Giese, Berndt Berndt Giese　 Univ. of Basel
Gin, David David Gin Sloan-Kettering Institute
Gribble, Gordon Gordon Gribble Dartmouth College
Grieco, Paul Paul Grieco Montana State Univ.
Grubbs, Robert Robert Grubbs (Bob) Caltech
Hamilton, Andrew Andrew Hamilton Yale Univ.
Hanessian, Stephen Stephen Hanessian (Steve) Univ. of Montreal
Harran, Patrick Patrick Harran (Pat) Univ. of Texas Southwestern Medical Center at Dallas
Hart, David David Hart (Dave) Ohio State Univ.
Hartwig, John John Hartwig Univ. of Illinois at Urbana-Champaign
Harwood, Lawrence Lawrence Harwood Univ. of Reading
Heathcock, Clayton Clayton Heathcock　 Univ. of California, Berkeley
Hecht, Sidney Sidney Hecht (Sid) Univ. of Virginia
Hegedus, Louis Louis Hegedus (Lou) Colorado State Univ.
Hiemstra, Henk Henk Hiemstra　 Univ. of Amsterdam
Hilvert, Donald Donald Hilvert (Don) ETH
Holmes, Andrew Andrew Holmes (Andy)　 Univ. of Melbourne
Holton, Robert Robert Holton (Bob) Florida State Univ.
Houk, Kendall Kendall Houk (Ken)　 UCLA
House, Herbert O. Herbert O. House (HO) Georgia Tech
Hoveyda, Amir Amir Hoveyda Boston College
Hoye, Thomas Thomas Hoye (Tom) Univ. of Minnesota
Hsung, Richard Richard Hsung Univ. of Wisconsin, Madison
Hudlicky, Tomas Tomas Hudlicky　 Brock Univ.
Ireland, Robert Robert Ireland (Bob) retired (Univ. of Virginia)
Jacobi, Peter Peter Jacobi Dartmouth College
Jacobsen, Eric Eric Jacobsen Harvard Univ.
Jamison, Tim Tim Jamison MIT
Johnson, William S. William S. Johnson (WS) deceased (Stanford Univ.)
Joullié, Madeleine Madeleine Joullié　 Univ. of Pennsylvania
Jung, Michael Michael Jung (Mike)　 UCLA
Kagan, Henri Henri Kagan　 retired (Univ. Paris-Sud)
Katritzky, Alan Alan Katritzky Univ. of Florida
Keck, Gary Gary Keck Univ. of Utah
Kelly, Ross Ross Kelly Boston College
Kende, Andrew Andrew Kende (Andy) Univ. of Rochester
Kiessling, Laura Laura Kiessling Univ. of Wisconsin, Madison
Knapp, Spencer Spencer Knapp　 Rutgers Univ.
Knochel, Paul Paul Knochel　 Ludwig-Maximilians-Univ. München
Kocienski, Philip Philip Kocienski (Phil)　 Univ. of Leeds
Kozlowski, Marisa Marisa Kozlowski Univ. of Pennsylvania
Kozmin, Sergey Sergey Kozmin Univ. of Chicago
Krische, Michael Michael Krische (Mike) Univ. of Texas at Austin
Lansbury, Jr. Peter Peter Lansbury, Jr. Harvard Univ.
Larock, Richard Richard Larock Iowa State Univ.
Lautens, Mark Mark Lautens Univ. of Toronto
Leighton, James James Leighton (Jim) Columbia Univ.
Leonard, Nelson Nelson Leonard deceased (Univ. of Illinois)
Ley, Steven Steven Ley (Steve) Cambridge Univ.
Liebeskind, Lanny Lanny Liebeskind Emory Univ.
Linderman, Russell Russell Linderman North Carolina State Univ.
Lipshutz, Bruce Bruce Lipshutz Univ. of California, Santa Barbara
List, Benjamin Benjamin List Max Planck Institute
MacMillan, David David MacMillan (Dave) Princeton Univ.
Magnus, Philip Philip Magnus (Phil) Univ. of Texas at Austin
Mander, Lewis Lewis Mander (Lew) Australian National Univ.
Marshall, James James Marshall Univ. of Virginia
Martin, Stephen Stephen Martin (Steve) Univ. of Texas at Austin
McDonald, Frank Frank McDonald Emory Univ.
Meinwald, Jerrold Jerrold Meinwald (Jerry) Cornell Univ.
Merrifield, Bruce Bruce Merrifield deceased (Rockefeller Univ.)
Meyers, Albert Albert Meyers (Al) Colorado State Univ.
Miller, Marvin Marvin Miller (Marv) Univ. of Notre Dame
Miller, Scott Scott Miller Yale Univ.
Mislow, Kurt Kurt Mislow Princeton Univ.
Molander, Gary Gary Molander Univ. of Pennsylvania
Molinski, Tadeusz Tadeusz Molinski Univ. of California, San Diego
Montgomery, John John Montgomery Univ. of Michigan
Mulzer, Johann Johann Mulzer Universität Wien
Myers, Andrew Andrew Myers (Andy) Harvard Univ.
Newman, Melvin Melvin Newman deceased (Ohio State Univ)
Nicolaou, Kyriacos C. Kyriacos C. Nicolaou (KC) The Scripps Institute
O'Donnell, Martin Martin O'Donnell　 Indiana Univ.-Purdue Univ. Indianapolis
Olah, George George Olah Univ. of Southern California
Overman, Larry Larry Overman Univ. of Califonia, Irvine
Padwa, Albert Albert Padwa (Al) Emory Univ.
Panek, James James Panek (Jim) Boston Univ.
Paquette, Leo Leo Paquette Ohio State Univ.
Parker, Kathlyn Kathlyn Parker (Kathy) SUNY, Stony Brook
Paterson, Ian Ian Paterson Cambridge Univ.
Pattenden, Gerald Gerald Pattenden (Gerry) Univ. of Nottingham
Pearson, William William Pearson (Will) Univ. of Virginia
Petasis, Nicos Nicos Petasis Univ. of Southern California
Phillips, Andy Andy Phillips Univ. of Colorado
Pirrung, Michael Michael Pirrung (Mike) Duke Univ.
Posner, Gary Gary Posner Johns Hopkins Univ.
Rawal, Viresh Viresh Rawal Univ. of Chicago
Rebek, Julius Julius Rebek The Scripps Institute
Reusch, William William Reusch Michigan State Univ.
Romo, Daniel Daniel Romo (Dan) Texas A&M Univ.
Roush, William William Roush (Bill) The Scripps Institute
Rychnovsky, Scott Scott Rychnovsky Univ. of Califonia, Irvine
Sammakia, Tarek Tarek Sammakia Univ. of Colorado
Sampson, Nicole Nicole Sampson SUNY, Stony Brook
Sanford, Melanie Melanie Sanford Univ. of Michigan
Schreiber, Stuart Stuart Schreiber (Stu) Harvard Univ.
Schrock, Richard Richard Schrock (Dick) MIT
Scott, Ian Ian Scott Texas A&M Univ.
Seebach, Dieter Dieter Seebach　 ETH
Seeberger, Peter Peter Seeberger　 ETH
Shair, Matthew Matthew Shair (Matt) Harvard Univ.
Sharpless, Barry Barry Sharpless The Scripps Institute
Sheehan, John John Sheehan deceased (MIT)
Sibi, Mukund Mukund Sibi North Dakota State Univ.
Siegel, Jay Jay Siegel Univ. of Zurich
Smith, Amos Amos Smith Univ. of Pennsylvania
Snapper, Marc Marc Snapper Boston College
Snider, Barry Barry Snider Brandeis Univ.
Snieckus, Victor Victor Snieckus　 Queen's Univ. (Canada)
Soderquist, John John Soderquist UCLA
Sorensen, Erik Erik Sorensen Princeton Univ.
Stang, Peter Peter Stang Univ. of Utah
Still, W. Clark W. Clark Still ex-Columbia Univ.
Stille, John K. John Stille (JK) Colorado State Univ.
Stoltz, Brian Brian Stoltz Caltech
Stork, Gilbert Gilbert Stork Columbia Univ.
Sulikowski, Gary Gary Sulikowski Vanderbilt Univ.
Swager, Timothy Timothy Swager (Tim) MIT
Taber, Douglass Douglass Taber (Doug) Univ. of Delaware
Takacs, James James Takacs (Jim) Univ. of Nebraska
Taylor, Edward C. Edward C. Taylor (EC) Princeton Univ.
Tietze, Lutz Lutz Tietze　 Univ. of Göttingen
Tius, Marcus Marcus Tius (Marc)　 Univ. of Hawaii
Toste, Dean Dean Toste Univ. of California, Berkeley
Totah, Nancy Nancy Totah Syracuse Univ.
Trauner, Dirk Dirk Trauner　 Univ. of California, Berkeley
Trost, Barry Barry Trost Stanford Univ.
Van Vranken, David David Van Vranken Univ. of Califonia, Irvine
Vasella, Andrea Andrea Vasella ETH
Vedejs, Edwin Edwin Vedejs (Ed)　 Univ. of Michigan
Vollhardt, Peter Peter Vollhardt Univ. of California, Berkeley
Wasserman, Harry Harry Wasserman Yale Univ.
Weinreb, Steven Steven Weinreb (Steve) Pennsylvania State Univ.
Wender, Paul Paul Wender Stanford Univ.
Wenkert, Ernest Ernest Wenkert (Ernie) retired (UCSD)
White, James James White (Jim) Oregon State Univ.
Williams, David David Williams (Dave) Univ. of Indiana
Williams, Robert Robert Williams (Bob) Colorado State Univ.
Winkler, Jeffrey Jeffrey Winkler (Jeff) Univ. of Pennsylvania
Wipf, Peter Peter Wipf Univ. of Pittsburgh
Woerpel, Keith Keith Woerpel Univ. of Califonia, Irvine
Wood, John John Wood Colorado State Univ.
Woodward, Robert B. Robert B. Woodward (RB) deceased (Harvard Univ.)
Zard, Samir Samir Zard Ecole Polytechnique
Zimmerman, Steven Steven Zimmerman (Steve) Univ.of Illinois at Urbana-Champaign