11李艳梅有机化学

Ether第十一章醚OrganicChemistryA(1)ByProf.LiYan-MeiTsinghuaUniversityContent11.1Structureandnomenclature11.2PhysicalandSpectralproperties11.3Chemicalreactions11.4Preparation11.5Epoxides11.6Sourceandusages11.1.1Structure11.1.2Classification11.1.3Nomenclature11.1Structureandnomenclature11.1.1Structure结构ORR'OHCH3OHHOH3CCH3Bondangle105o108.9o111.7oOatomsp3hybridizationtwounsharedpair11.1.2Classification分类ORR'R=R’Symmetricether/Simpleether简单醚R≠R’Asymmetricether混合醚ORconnectedwithR’Epoxide环醚（环氧化物）11.1.3Nomenclature命名(A)无环单醚ODiethyletherDiphenyletherOmethylethyletherOisobutylsecbutylether普通命名法甲基乙基醚异丁基仲丁基醚IUPAC定主链编号书写OO123OO1,2-dimethoxyethane1,2-二甲氧基乙烷OO3-methoxyprop-1-eneOcyclopentyloxybenzenemethoxyethaneOOHOCH3OHOHOH4,6-dimethoxyhexane-1,2,3,5-tetraol多羟基化合物醚的命名法OCH3OHOCH3OCH3OHOCH3OHglycolmethyletherglycoldimethyletherglycenol-1-methyletherOCH3OHOHglycenol-2-methyletherOCH3OCH3OHglycenol-1,2-methylether乙二醇一甲醚乙二醇二甲醚丙三醇-2-甲醚丙三醇-1-甲醚丙三醇-1,2-二甲醚(B)环醚（环氧化物）：“环氧某烃”OOCH3OCH2ClOO环氧乙烷oxirane1,2-环氧丙烷1,2-epoxypropane3-氯-1,2-环氧丙烷3-chloro-1,2-epoxypropane1,3-环氧丙烷1,3-epoxypropane1,4-环氧丁烷1,4-epoxybutaneOOO1,4-dioxanetetrahydrofuran1,4-二氧六环四氢呋喃Crownether冠醚m-crown-nm-冠-nx:thetotalnumberofatomsinthering环的总原子数y:thenumberofoxygenatoms环中的氧原子数OOOOOOOOOOOOOOOO12-crown-412-冠-4OOOOOO18-crown-618-冠-611.2PhysicalandSpectralproperties11.2.1Physicalproperties醚分子间不形成氢键，但可与水分子形成氢键非直线型：极性分子比重大，闪点低乙醚可作为麻醉剂11.2.1Spectroscopicdata11.3.1Autooxidation11.3.2Basicity11.3.3Etherbondcleavage11.3.4Claisenrearrangement11.3Chemicalreactions11.3.1Autooxidation自动氧化OHO2OOOHpolymerizeOOn过氧化物的鉴别：1，淀粉碘化钾试剂Starchiodidepaper2，硫酸亚铁－氰化钾试剂氢过氧化乙醚过氧化乙醚（爆炸性极强）处理：蒸馏前先加入5％FeSO4洗至无过氧化物预防：加入对苯二酚或二乙基氨基二硫代甲酸钠11.3.2Basicity碱性ROR'H+RHOR'iceROR'常用于分离提纯醚形成“好”的离去基团Abilitytoformoxonium形成钅羊盐的能力ROR'ArORArOAr11.3.3Etherbondcleavage醚键断裂ReactionMechanism1oRSN2H3COCH3HXH3CHOCH3X-CH3X+CH3OHHXCH3XROR'RX+R'OHHXHXR'X3oRSN1OHXHO+HOCH3CH3XXHXHXReactivity1）氢卤酸使醚链断裂能力HIHBrHCl常用试剂：57％HI或KI+H3PO42）碳氧键断裂顺序三级烷基二级烷基一级烷基苯基O1molHI+HOCH3CH3XXHI1molHIICH3+HIOOHI3）环醚OHIIOHHIIIHBrORBrOHR+HOBrR4）苄基醚在催化加氢条件下氢解ORH2/Pd/COHR+11.3.4Claisenrearrangement克莱森重排OOH123123ReactionO123123OH迁移到邻位，如果两个邻位均被占据，则迁移到对位。MechanismabcOabcOabcOOHabcH协同过程OabcOabcOHabcOHabcExamplesO123OH123RR123OOH123RRabcOabcOabcOOHabcH反应特征：OabcOabc反应的核心：反应核心的推广：OO11.4PreparationWilliamson合成法醇分子间失水烯烃加醇RONa+R'XRO-R'+NaXRONa+R'OSO3HRO-R'+NaOSO3H11.5.1Epoxideanditsderivatives环氧化物及其衍生物(A).PreparationO2,Ag250oCOORRCOOOHR+RCOOHOHBrNaOH,H2OO11.5Epoxides环氧化物BrOHBrOHNaOHH2OBrOORHOHBrHRNaOHH2OORHRHStereochemistry反式共平面(B).Ringopening开环反应1.Acidcatalyzedringopening酸催化开环SN2反应，但是具有SN1反应的性质。OHHRHH+OHHHRHOHHHRHNuOHHHRHNu:O+H2OH+OHOH+CH3OHH+OCH3OH+C6H5OHH+OC6H5OH+HXH+XOH+HCNH+CNOHExamplesO+B2H6H+OBH2HBH2OBOOOH2OOH2.Basecatalyzedringopening：碱催化开环试剂一般为碱，活泼，亲核力强。OHHRHNu:OHHRHNu:HHRHONu进攻方向：空间位阻较小的碳即取代基较少的碳原子OHHRHOHOHOHROOHORArORMgXOHOArOHRNH3NH2ROHNHROHNH2ExamplesOHHRHLiAlH4OAlH3LiOAlLi4H2OOH+LiAlO2(C)Usage用途实验室：制备双官能团化合物工业上：制乙二醇O+H2OH+OHOH制聚乙二醇OnSnCl4H2OHO(CH2CH2O)nH制非离子表面活性剂RONa+nORO(CH2CH2O)nH11.5.2Crownether冠醚(A).Preparation制备OOOOOOHOOOHOOOClCl+RONa(B).Character性质1，特定的孔穴尺寸——萃取2，双亲性——相转移催化剂OOOOOOHOOOHOOOClCl+RONaOOOOOO亲水部分亲油部分(C)Usage用途1，萃取2，相转移催化剂RX+NaCNCrownetherRCN+NaXinwaterinwaterNaCNNa+RCNRXWaterOrganicNaCN+冠+X-冠－CN-+Na+冠+CN-+RXRCN+冠－X-