中国农业大学有机化学课件第十章 醇酚醚.ppt

Chapter 10. Alcohols, Phenols and Ethers 10.2 Elimination 320-350 ℃ 200 ℃ ② Through chlorobenzene 425 ℃ ③ Through oxidation of iso-propylbenzene 110-120℃ 80-90℃ 10.3.4.2 Hydroquinone Principle of development ? manufacture 10.3.4.3 a – naphthol and b - naphthol ? - naphthol ? - naphthol ? manufacture: 200℃,1.4MPa ? - naphthol ? - naphthol 10.4 Ethers 10.4.1 structure and nomenclature 通式 R – O–R′ （R = R′ 单醚；R ? R′混合醚） ′ 110℃ nomenclature： Common nomenclature (usually used for simple ethers) eg. 甲醚 苯醚 异丙醚 甲基叔丁基醚 苯甲醚 IUPAC name（for perplexing ethers） eg. 2-甲氧基-3-乙基己烷 4-羟基-3-甲氧基苯甲醛(香兰素) ? name of cyclic ethers: 环氧乙烷 四氢呋喃1,4-环氧丁烷 二噁烷1,4-二氧六环 ? name of polyethers ： 乙二醇甲乙醚 二缩二醇单甲醚 10.4.2 Physical properties of ethers 10.4.3 Chemical properties 10.4.3.1 Formation of protonated ethers Formation of complexes with Lewis acid ： Catalyst used in Fridel-Crafts substitution 10.4.3.2 cleavage of ether bond (as protecting group) 130-140℃ 120-130 ℃ 10.4.3.3 Formation of peroxide 10.4.4 Preparation of ethers 10.4.4.1 Dehydration between two alcohols Primary alcohol——SN2 Secondary alcohol——SN1 Tertiary alcohol：alkene will be producedCyclic ethers will be produced from diols under same conditions： e.g. 10.2.1.3 The competition of elimination and nucleophilic substitution (1) structural factors (2) Strength of the alkali used strength of alkalis in common use： NH2ˉ ROˉ HOˉ CH3COOˉ Iˉ (3) Polarity of the solvent used： 极性大不利于电荷分散，因此不利于消除 反应物 温度/°C 无水乙醇 % 含20%水的乙醇 % 历程 (CH3)3C-Br 25 19.6 12.6 E1 (CH3)2CH-Br 55 71 59 E2 (4) Temperature Higher temperature is in favor of elimination 10.2.1.4 Stereochemistry of elimination E1：no stereoselectivity E2：anti-elimination 10.2.1.5 Hot elimination 200～500°C mechanism Attestations： 10.2.2 ?-elimination carbene