第十二章羧酸

1、n羧酸的分類和命名羧酸的分類和命名n羧酸的結(jié)構(gòu)與制法羧酸的結(jié)構(gòu)與制法n羧酸的化學(xué)反應(yīng)羧酸的化學(xué)反應(yīng)n羥基酸的化學(xué)特性羥基酸的化學(xué)特性RCOHO脂肪羧酸脂肪羧酸按烴基分按烴基分芳香羧酸：芳香羧酸： Ar-COOH飽和羧酸：飽和羧酸：CH3COOH不飽和羧酸：不飽和羧酸：CH2=CH-COOH按羧基數(shù)目分按羧基數(shù)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鍵鍵p 、共軛共軛孤對(duì)孤對(duì)電子電子RCOHO.COORHp 、共軛體系共軛體系C=

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

3、備比 RX 多一碳的羧酸多一碳的羧酸RMgXCO2(RCO2)2MgH2ORCO2HRXMgOHNaOHOHCO2HOHCO2H加加壓壓CO2120-140oCOHK2CO3OHCO2KCO2200 300oCOHCO2HH+OHCOOH240oCOHCO2KK2CO3OHCO2HH+CHCOOHRHR COOHArOHROH RCOOHB:RCOORCOORCOO有兩個(gè)完全有兩個(gè)完全等價(jià)的共振式等價(jià)的共振式COOHCOOHNO2COOHNO2COOHCH3ABCDBCAD練習(xí)：比較下列化合物的酸性COOHpKaOHOOCOOHOHC1/2-1/2-4.172.98形成分子內(nèi)氫鍵，形成分子內(nèi)氫

4、鍵，有利于羧酸負(fù)離子有利于羧酸負(fù)離子穩(wěn)定，酸性增加穩(wěn)定，酸性增加吸電子吸電子誘導(dǎo)效應(yīng)誘導(dǎo)效應(yīng)給電子給電子誘導(dǎo)效應(yīng)誘導(dǎo)效應(yīng)場(chǎng)效應(yīng)場(chǎng)效應(yīng)場(chǎng)效應(yīng)場(chǎng)效應(yīng)誘導(dǎo)效應(yīng)誘導(dǎo)效應(yīng)RCOOHRCOXRCOORCOORRCONH2(R)CRORCOOHRCOClSOCl2PCl3PCl5RCOOHPBr3RCOBrROHSOCl2RClPBr3RBrRCH2COOHRCH2COOCCH2ROP2O52+ + H2ORCOORRCOOHHOR H2O+H+RCOORRCOOHHOR- - H2OHRCOHOH親親核核加加成成RCOHOHHORRCOHOHORHRCOORRCOHOHHH2O+ + H3ORCOHOCR

5、2R1R3RCOOCR2R1R3RCOOCR2R1R3OH+H*( )鹽酸催化下，羧酸與甲醇酯化的相對(duì)速度：鹽酸催化下，羧酸與甲醇酯化的相對(duì)速度： n 羧酸與醇的結(jié)構(gòu)對(duì)酯化反應(yīng)的影響羧酸與醇的結(jié)構(gòu)對(duì)酯化反應(yīng)的影響反應(yīng)活性順序：反應(yīng)活性順序：醇：醇：CH3OH RCH2OH R2CHOH酸：酸：CH3COOH RCH2COOH R2CHCOOH R3CCOOH HORH2OR- - H2ORRCOOHRCOOHRRCOORRCOORHHH2O+ + H3ORCOOH+RCOORRRCOOH+RCOOH3CCH3CCH2CCH3CH3CH3HCH3CH3CCH3RCOOHHRCOHOCCH3CH3

6、CH3 H酯的應(yīng)用酯的應(yīng)用RCOOHNH3RNH2RCOONH4RCONH2RCOONH3R- - H2ORCONHR100oC180190oC- - H2ORNH2RCONHRRCOClRCOOCRORCOOHSOCl2P2O5RCOOLiH2AlHRCOAlH2OHLiRCOH- - LiOAlH2RCOOHLiAlH4 H2LiH3AlHRCOAlH3LiHHH2ORCH2OHRCOOHLiAlH4RCH2OHH2O 合成上由羧酸合成上由羧酸制備伯醇，宜先酯制備伯醇，宜先酯化再還原化再還原RCH2OHRCOOHRCOOEt1. LiAlH4酯酯化化2. H2O1. LiAlH42. H2

7、ORCOOHLiAlH4B2H6RCH2OHH2OH2OCOOHB2H6O2NH2OCH2OHO2NRCOOH(1) NaOH(2)RHCO2+ ROHOORRRORRHCO2+ COOHCu喹啉COOHH2OO2NNO2NO2O2NNO2NO2加熱反應(yīng)即發(fā)生加熱反應(yīng)即發(fā)生COOHCOOHOOOCOOHCOOHOOO+H2O+H2O COOHCOOHCOOHCOOH+CO2 HCOOHH3C+ CO2CH3CH2COOHCOOHCOOHCOOHCOOH+H2OO+CO2O +H2O+CO2 布朗克（布朗克（Blanc）規(guī)則：）規(guī)則：有機(jī)反應(yīng)中有成有機(jī)反應(yīng)中有成環(huán)環(huán)可能時(shí)，可能時(shí)，一般形成一般形

8、成五元或六元環(huán)五元或六元環(huán)+X23 PX33 RCH2COOH+ PX3+ P(OH)3RCH2COXRHCCOHXH+XXRCH2COHXXRCHCOXXRCH2COOHRCHCOOHX- - HRCH2COX+烯烯醇醇化化交交換換2 PRCH2COX3RHCCOOHHX2 / P or SRHCCOOHXX = Br , ClCOOHBrCOOHBr2FeBr3COOH+Cl2Fe加熱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 掌握羧酸的分類、命名、結(jié)構(gòu)與酸性掌握羧酸的分類