第十二章羧酸

1、n羧酸的分类和命名羧酸的分类和命名n羧酸的结构与制法羧酸的结构与制法n羧酸的化学反应羧酸的化学反应n羟基酸的化学特性羟基酸的化学特性RCOHO脂肪羧酸脂肪羧酸按烃基分按烃基分芳香羧酸：芳香羧酸： Ar-COOH饱和羧酸：饱和羧酸：CH3COOH不饱和羧酸：不饱和羧酸：CH2=CH-COOH按羧基数目分按羧基数目分一元羧酸：一元羧酸：CH3COOH二元羧酸：二元羧酸：多元羧酸：多元羧酸：COOHCOOHCOOHCOOHHO-C-COOHHCOOHCH3COOHCH3(CH2)14COOHCH3(CH2)16COOH键键p 、共轭共轭孤对孤对电子电子RCOHO.COORHp 、共轭体系共轭体系C=

2、O 0.123nmC-O 0.136nmRCOHOORCHOCH3CH2CH2CH2OHKMnO4/H2SO4CH3CH2CH2CHOKMnO4/H2SO4CH3CH2CH2COOHCH2OHKMnO4/H2SO4CHOKMnO4/H2SO4COOHCH3CHCHCHOAgNO3,NH3CH3CHCHCOOHBrCH2CH2BrNCCH2CH2CNH2OH+HOOCCH2CH2COOHClCH2COONaNaCNNCCH2COONa(1) NaOH(2) H2O / H+HOOCCH2COOH2 NaCNC3H7CHOHCNC3H7CHOHCNH2O, HClC3H7CHOHCOOH 制备比制

3、备比 RX 多一碳的羧酸多一碳的羧酸RMgXCO2(RCO2)2MgH2ORCO2HRXMgOHNaOHOHCO2HOHCO2H加加压压CO2120-140oCOHK2CO3OHCO2KCO2200 300oCOHCO2HH+OHCOOH240oCOHCO2KK2CO3OHCO2HH+CHCOOHRHR COOHArOHROH RCOOHB:RCOORCOORCOO有两个完全有两个完全等价的共振式等价的共振式COOHCOOHNO2COOHNO2COOHCH3ABCDBCAD练习：比较下列化合物的酸性COOHpKaOHOOCOOHOHC1/2-1/2-4.172.98形成分子内氢键，形成分子内氢

4、键，有利于羧酸负离子有利于羧酸负离子稳定，酸性增加稳定，酸性增加吸电子吸电子诱导效应诱导效应给电子给电子诱导效应诱导效应场效应场效应场效应场效应诱导效应诱导效应RCOOHRCOXRCOORCOORRCONH2(R)CRORCOOHRCOClSOCl2PCl3PCl5RCOOHPBr3RCOBrROHSOCl2RClPBr3RBrRCH2COOHRCH2COOCCH2ROP2O52+ + H2ORCOORRCOOHHOR H2O+H+RCOORRCOOHHOR- - H2OHRCOHOH亲亲核核加加成成RCOHOHHORRCOHOHORHRCOORRCOHOHHH2O+ + H3ORCOHOCR

5、2R1R3RCOOCR2R1R3RCOOCR2R1R3OH+H*( )盐酸催化下，羧酸与甲醇酯化的相对速度：盐酸催化下，羧酸与甲醇酯化的相对速度： n 羧酸与醇的结构对酯化反应的影响羧酸与醇的结构对酯化反应的影响反应活性顺序：反应活性顺序：醇：醇：CH3OH RCH2OH R2CHOH酸：酸：CH3COOH RCH2COOH R2CHCOOH R3CCOOH HORH2OR- - H2ORRCOOHRCOOHRRCOORRCOORHHH2O+ + H3ORCOOH+RCOORRRCOOH+RCOOH3CCH3CCH2CCH3CH3CH3HCH3CH3CCH3RCOOHHRCOHOCCH3CH3

6、CH3 H酯的应用酯的应用RCOOHNH3RNH2RCOONH4RCONH2RCOONH3R- - H2ORCONHR100oC180190oC- - H2ORNH2RCONHRRCOClRCOOCRORCOOHSOCl2P2O5RCOOLiH2AlHRCOAlH2OHLiRCOH- - LiOAlH2RCOOHLiAlH4 H2LiH3AlHRCOAlH3LiHHH2ORCH2OHRCOOHLiAlH4RCH2OHH2O 合成上由羧酸合成上由羧酸制备伯醇，宜先酯制备伯醇，宜先酯化再还原化再还原RCH2OHRCOOHRCOOEt1. LiAlH4酯酯化化2. H2O1. LiAlH42. H2

7、ORCOOHLiAlH4B2H6RCH2OHH2OH2OCOOHB2H6O2NH2OCH2OHO2NRCOOH(1) NaOH(2)RHCO2+ ROHOORRRORRHCO2+ COOHCu喹啉COOHH2OO2NNO2NO2O2NNO2NO2加热反应即发生加热反应即发生COOHCOOHOOOCOOHCOOHOOO+H2O+H2O COOHCOOHCOOHCOOH+CO2 HCOOHH3C+ CO2CH3CH2COOHCOOHCOOHCOOHCOOH+H2OO+CO2O +H2O+CO2 布朗克（布朗克（Blanc）规则：）规则：有机反应中有成有机反应中有成环环可能时，可能时，一般形成一般形

8、成五元或六元环五元或六元环+X23 PX33 RCH2COOH+ PX3+ P(OH)3RCH2COXRHCCOHXH+XXRCH2COHXXRCHCOXXRCH2COOHRCHCOOHX- - HRCH2COX+烯烯醇醇化化交交换换2 PRCH2COX3RHCCOOHHX2 / P or SRHCCOOHXX = Br , ClCOOHBrCOOHBr2FeBr3COOH+Cl2Fe加热COOHCl /CH3COOHCl2ClCH2COOHCl2CHCOOHCl3CCOOHCl2Cl2+日 光日 光日 光一 氯 乙 酸二氯 乙 酸三 氯 乙 酸CHCOOHX酯酯化化ZnCHCOORZnXRRCHCOORXRH3O+R(R)HOCHCOORZnXR+R(R)HOZnBrCHCOORRR(R)HOHCHCOORRH3CCOOCH3O + BrCH2COOCH3(1)Zn/Et2O(2)H3O+H3CCOOCH3OHCH2COOCH3ROOH ROOH OH2OOOORROHH+ROOH OOOHORROH H+OOH ROHH+OOR 掌握羧酸的分类、命名、结构与酸性掌握羧酸的分类