Organic chemistry Alcohols Ethers and Phenols Organic chemistry

有机化学 Organic chemistry 第九章 醇、酚、醚 Alcohols, Ethers and Phenols 主讲老师：刘玉霞

有机化学 Organic chemistry ROH Alcohols 醇 Ar. OH Phenols 酚 R-O-R’ Ether 醚 Compounds that have hydroxyl group bonded to a saturated, sp 3 -C atom. Compounds that have hydroxyl group bonded to a aromatic ring. Compounds that have a oxygen atom bonded to two carbon atom

有机化学 Organic chemistry 9. 1 Structure、Classification and Nomenclature of Alcohols 9. 1. 1 Structure of Alcohols sp 3杂化 C－O σ键

有机化学 Organic chemistry 9. 1. 2 Classification of Alcohols (1) Type of Connected Alkyl Group 醇 alcohol 脂肪醇 aliphalic 芳香醇 aromatic 饱和醇 saturated 丁醇 不饱和醇 unsaturated 烯丙醇 2–丙炔醇 2–苯基乙醇

有机化学 Organic chemistry (2) Type of Connected Carbons Primary alcohols Secondary alcohols Tertiary alcohols (3) Numebers of Hydroxyl Group 乙 醇 一 元醇 乙 二醇 二 元醇 丙 三醇 三 元醇

有机化学 Organic chemistry 9. 1. 3. Nomenclature of Alcohols (1) Common name: Alkyl + alcohol 甲醇 (methyl alcohol) 异丁醇 (isobutyl alcohol) 烯丙醇 (allyl alcohol) 苯甲醇 苄醇 (benzyl alcohol)

有机化学 Organic chemistry 练 一 练 异丙醇 isopropyl alcohol 叔丁醇 tert-Butyl alcohol 炔丙醇 (propargyl alcohol) 环己醇 cyclohexyl alcohol

有机化学 Organic chemistry (2) IUPAC Nomenclature a) Number: begin at the end nearer the hydroxyl group. 1 2 3 3 2 4 1 Cl. CH 2 CH 2 OH 3–甲基– 2–丁醇 (3 -methyl-2 -butanol) (3 -氯-1 -丙醇) 3 -Chloro-1 -propanol 1 2 3 (2 -甲基-2 -丙醇) 2 -methyl-2 -propanol

有机化学 Organic chemistry 9. 3 Chemical Properties of Alcohols 弱碱性 亲核取代 反应 Nu: 氧化反应 消除反应 质子化 弱酸性

有机化学 Organic chemistry 9. 3. 1 Acidity and Basicity of Alcohols Like water, alcohols are both weakly basic and weakly acidic. An alcohol An oxonium ion As a weak acid: Acid (base) conjugate base conjugate acid

有机化学 Organic chemistry In any proton-transfer process: Stroger + Stroger acid base K>1 Weaker + Weaker acid base acidity：alcohol<water CH 3 OH> Primary > Secondary> Tertiary

有机化学 Organic chemistry 9. 3. 2 Conversion of Alcohols to Halides 1. 与氢卤酸的反应 醇与氢卤酸反应, C―O 键断裂，C―X键生成： 反应相对活性： HX: HI > HBr > HCl

有机化学 Organic chemistry 9. 3. 5 Oxidation and Dehydrogenation A. Oxidation of primary alcohols

有机化学 Organic chemistry Sarett，PCC 试剂可将伯醇氧化成醛： PCC reagent is soluble in CH 2 Cl 2 PCC doesn’t attack C=C bond 香茅醇 香茅醛 (82%)

有机化学 Organic chemistry B. Oxidation of secondary alcohols Secondary alcohols [O] C. Oxidation of Tertiary alcohols ketones

有机化学 Organic chemistry Ag. IO 3 Ag. NO 3 is added to identify the vicinal diols 3. 频哪醇重排 重排

有机化学 Organic chemistry 9. 5 Preparation of Alcohols Transformation of the several functional groups to alcohols: 9. 5. 1 Via reaction of alkenes

有机化学 Organic chemistry 9. 5. 2 Grinard Synthesis 环氧乙烷 邻甲基苯乙醇(66%)

有机化学 Organic chemistry 9. 5. 3 Via Hydrolysis of Alkyl Halides It is rarely used for the synthesis of alcohol, since alkyl halides are normally prepared from alcohols. 9. 5. 4 Via Reduction of Carbonyl Compounds or Derivatives of Carboxylic Compounds (1) Hydrogenation of aldehydes and ketones by Catalysis of metals

有机化学 Organic chemistry Aldehydes Ketones p-Methoxybenzaldehyde Primary alcohols Secondary alcohols p-Methoxybenzyl alcohol(92%)

有机化学 Organic chemistry (2) Reduction of carbonyl compounds by metal hydrides Sodium borohydride Na. BH 4 (硼氢化钠) Butanal Lithium aluminum hydride Li. Al. H 4(LAH) (四氢铝锂) 1 -Butanol (87%)

有机化学 Organic chemistry 4, 4 -Dimethyl 2 -pentanone Selective reduction: Na. BH 4 does not reduce C=C, －COOR。 Li. Al. H 4 does not reduce C=C, 4, 4 -Dimethyl 2 -pentanol(85%) and －COOH,

有机化学 Organic chemistry CH 3 CH=CHCHO H 2, Ni CH 3 CH 2 CH 2 OH 丁醇 Al[OCH(CH 3)2]3 (CH 3)2 CHOH溶剂 CH 3 CH=CHCH 2 OH 巴豆醇 肉桂醛 肉桂醇

有机化学 Organic chemistry 9. 8 Structure、Classification and Nomenclature of Phenols 1. Structure of phenols O: sp 2 hybride p, π–conjugation 苯酚的结构示意图

有机化学 Organic chemistry 2. Classification and Nomenclature of Phenols Mono phenols: aryl + “phenol” 4 -Methylphenol 5 -Chloro-2 -methyl-phenol p-Methylphenol 2 -甲基-5 -氯苯酚 1 -Naphthol α- Naphthol 2 -Naphthol β- Naphthol

有机化学 Organic chemistry Diphenols 1, 2 -Benzenediol 1, 4 -Benzenediol 1, 3 -Benzenediol Hydroquinone Catechol Resorcinol 儿茶酚 对苯二酚 间苯二酚 邻苯二酚 氢醌 Trihydric phenol Pyrogallol 1, 3, 5 -benzenetriol 连苯三酚 均苯三酚

有机化学 Organic chemistry 9. 9 Physical Properties of Phenols The formation of hydrogen bond! 溶解度：在水中部分溶解。 熔、沸点：高于分子量相近的烃。 波谱性质： 1. 红外（IR） O―H： 3640～ 3200 cm-1(宽峰)； C―O： 1200 cm-1。 芳 环： 1500～ 1600 cm-1。 2. 核磁 (H-NMR)：-OH，δ值在 4 -8之间。 Ar-H: δ值在 7 -8之间。

有机化学 Organic chemistry σ/ cm-1 1600 1500 1450 图 9. 5 苯酚的红外光谱图

有机化学 Organic chemistry 9. 10 Chemical Properties of Phenols Acylation Acidity Formation of aryl ethers Aromatic Electrophilic Substitution

有机化学 Organic chemistry 9. 10. 1 Acidity of phenols 想一想 酚的酸性到底有多大？

有机化学 Organic chemistry Acidity： H 2 CO 3 ＞ 酚 >H 2 O＞ 醇 Why ? p. Ka： ≈6. 4 ≈10 ≈18 酚负离子中电子离域：p , π–conjugation Substituted phenols: on the position o- or p. Electron-releasing group Acidity Electron–withdrawing group Acidity

有机化学 Organic chemistry Table 1 The acidity constants of phenols p. Ka (25℃) Substimptuents o- -H -CH 3 9. 89 Substituents 2, 4 -Dinitro p. Ka (25℃) 3. 96 10. 20 10. 01 10. 17 -Cl 8. 11 -NO 2 7. 17 -OCH 3 9. 98 9. 20 2, 4, 6 -Trinitro 8. 28 7. 15 (picric acid) (苦味酸) 9. 65 10. 21 8. 80 0. 38

有机化学 Organic chemistry 9. 10. 2 Acylation of phenols and Fries rearrangement Acylating agents: acyl halides and carboxylic acid anhydrides Fries rearrangement: Conversion of aryl esters to aryl ketones.

有机化学 Organic chemistry 9. 10. 3 Electrophilic aromatic substitutions Sulfonation Nitration Halogenation Alkylation Acylation Types of electrophilic aromatic substitution of benzene

有机化学 Organic chemistry 1. halogenation Hydroxyl group is a powerful activating substituent (100%) 用于苯酚的定量、定性鉴定

有机化学 Organic chemistry 2. Sulfonation 15 -25 o. C H 2 SO 4 浓 80 -100 o. C H 2 SO 4（稀） Reflux H 2 SO 4（浓） 80 -100 o. C

有机化学 Organic chemistry Application 2, 4, 6 -三硝基苯酚（苦味酸）的制备 浓H 2 SO 4 HNO 3 100 o. C 苦味酸

有机化学 Organic chemistry 5. Phenolic resin

有机化学 Organic chemistry 补充反应： 1. Kolbe-Schmitt reaction：Carboxylaltion of phenols Sodium phenoxide Heated under pressure CO 2 Acidified Salicylic acid Aspirin 阿斯匹林 乙酰水杨酸 Salicylic acid 水杨酸 79%

有机化学 Organic chemistry 2. Preparation of aryl ethers Williamson Method A Phenoxide anion A alkyl halide Alkylation of hydroxyl oxygen a phenol Why?

有机化学 Organic chemistry 3. Oxidation of phenols: Quinones 醌 Hydroquionoe p-Benquinone 9. 11 Preparation of phenols 1. Industrial synthesis (1) Reaction of benzenesulfonic acid with Na. OH

有机化学 Organic chemistry 碱熔法 Toluene p-Toluenesulfonic acid p-methylphenol (72%) (2) Hydrolysis of chlorobenzene (3) From cumene（枯烯）

有机化学 Organic chemistry Cumene hydroperxide (氢过氧化枯烯) Cumene is oxidized to cumene hydroperoxide

有机化学 Organic chemistry 2. Laboratory synthesis 9. 12 Important phenols From aniline: (80%)

有机化学 Organic chemistry 9. 13 Structure、Classification and Nomenclature of Ethers 1. Structure H CC H O H C H H 甲醚的结构 H

有机化学 Organic chemistry 2. Classification and Nomenclature Class of Ethers: Epoxides (1) Symmetrical ethers ：(di) + “alkyl” ＋ “ether” (二)甲醚 二苯醚 (二)乙醚 (diethyl ether) (dimethyl ether) (diphenol ether)

有机化学 Organic chemistry (2) Unsymmetrical (Mixed) ethers Simple mixed ethers：“alkyl” ＋ “ether” 甲基叔丁醚 tert-butyl methyl ether 优先的基团放 在后面 苯乙醚 Ethyl phenyl ether 若有芳基，应将芳 基放在前面

有机化学 Organic chemistry Other mixed ethers ：烃氧基作取代基 。 2–甲氧基戊烷 (2 -methoxypentane) 4–乙氧基甲苯 (1 -ethoxy-4 methylbenzene) (3) Cyclic ethers: 1, 4 -Dioxane Tetrahydrofuran Epoxides 1, 4 -二氧六环 (THF)(四氢呋喃) 环氧乙烷

有机化学 Organic chemistry T /% 9. 14 Physical Properties of Ethers 波数/cm-1 图 9. 7 正丙醚的红外光谱图 IR: C―O 1275 ~ 1020 cm-1

有机化学 Organic chemistry a 3. 37 b 1. 59 c 0. 93 δ 1 H NMR: -CH 2 O图 9. 8 正丙醚的核磁共振谱图 δ 3. 4 ~ 4. 0 ppm

有机化学 Organic chemistry 9. 15 Physical Properties of Ethers 1. Oxidation 2. Acid-catalyzed cleavage of ethers Mechanism of the reaction: Oxonium salt

有机化学 Organic chemistry Cleavage of aryl ethers by hydrogen halides The bond of O－R was broken!

有机化学 Organic chemistry The bond of C－O in phenols has partial double bond character 3. Reactions of epoxides A. Base-catalyzed ring opening

有机化学 Organic chemistry To the unsymmetric epoxide, in basecatalyzed ring-opening, attack by nucleophile oc c ur s at less substituted c a r b o n a t o m. B. Acid-catalyzed ring opening In the acid-catalyzed ring opening, the nucleophile attacks primarily at the more substituted carbon atom. Stereoselectivity: Anti-hydroxylation

有机化学 Organic chemistry SN 2 reaction With inversion of configuration

有机化学 Organic chemistry 9. 16 Preparation of Ethers 1. By intermolecular dehydration of alcohols Substrate: Primary alcohols Acid-catalyzed Products: symmetric ethers 2. The Williamson Synthesis of Ethers Sodium alkoxide, Alkyl halide and derivatives (Asymmetric) Mixed ethers

有机化学 Organic chemistry

有机化学 Organic chemistry The reaction characteristic: 1. SN 2 reaction 2. 2. The best substrate is primary alkyl halide

有机化学 Organic chemistry 3. Preparation of Aryl ethers Claisen L. Rearrangement

有机化学 Organic chemistry 9. 17 Cyclic Ethers 四氢呋喃 (THF) 1, 4–二氧六环 冠醚：含有多个氧的大环醚 9. 18 Sulfides（略） 环氧乙烷 (ethylene oxide)