有机化学缩合反应

1、CHRCROHBCHRCROCHRCROCHRCROOHBCHRCROOCHRCROOCHRCROD2OX2CH2RCROCHRCRODCHRCROXCHCROCROHRCH2RCCOCCCOCHCOCCCORCLORXCCORCOCCORRCH2CORORCH CORORCH2COCH CORORH+ HORORH3CCOOC2H52（1）Na / C2H5OHCOOC2H5H3CCO（2） 50% HOAcCH2NaOC2H5CH3(CH2)3COCHCO2C2H5CH2CH2CH32CH3CH2CHCO2C2H5CH3NaCH3CH2CHCCH3COCH3CH2CH3CO2C2H52CH

2、3(CH2)3CO2C2H5Ph3CCH2COOC2H5RRCOOC2H5强强碱碱（化化学学计计量量）无无 氢氢CHCOOC2H5CORRHCCOOC2H5R（使使不不可可逆逆）有有 氢氢CH2COORRCH2COORR+碱碱四四种种产产物物均均有有 氢氢（1）甲酸酯）甲酸酯HCOOC2H5+H CH2COC2H5OEtONaHCOCH2COOC2H5H2O-3H2OCOOC2H5H5C2OOCCOOC2H5醛基醛基OHOH+ HCOEtOO-HHCO2ROHOHCHOOHOHCH2OHRO-0-25oCNaHH2ONaBH4C2H5OH 25oC *1. 甲酸酯中含有醛基、催化剂碱性不能太强

3、，产率不高甲酸酯中含有醛基、催化剂碱性不能太强，产率不高. *2. 是在分子中引入甲酰基的好方法是在分子中引入甲酰基的好方法. *3. 如果用一个环酯和甲酸酯缩合，不能用如果用一个环酯和甲酸酯缩合，不能用RO-做催化剂，做催化剂， 否则会发生酯否则会发生酯 交换而开环交换而开环.讨讨 论论*1. 一个酯羰基的诱导效应，增加了另一个酯羰基的活性，一个酯羰基的诱导效应，增加了另一个酯羰基的活性， 反应顺利，产率好。反应顺利，产率好。*2. 羰基活性好，所以催化剂的碱性不用太强。羰基活性好，所以催化剂的碱性不用太强。*3. 在合成上用来制备在合成上用来制备 丙二酸酯或丙二酸酯或-取代的丙二酸酯。取代

4、的丙二酸酯。 -羰基酸。羰基酸。（2）草酸酯）草酸酯丙二酸酯丙二酸酯-羰基酸羰基酸+H CH2COC2H5OEtONaH2OCOOC2H5COH5C2OCOCH2COC2H5OCOH5C2OHO-H+COCH2COOHCOHOCOCH3COHO175 oCCOCH2COC2H5OH5C2O*1. 羰基活性差，应选用强一些的碱作催化剂。羰基活性差，应选用强一些的碱作催化剂。*2. 在合成上用来制备丙二酸酯或在合成上用来制备丙二酸酯或-取代的丙二酸酯取代的丙二酸酯。(3) 碳酸酯碳酸酯H5C2OCOOC2H5+H CH2COC2H5OEtONaH5C2OCOCH2COC2H5OH2O*1. 羰基活

5、性差，选用强碱作催化剂。羰基活性差，选用强碱作催化剂。*2. 在合成上，主要用于在在合成上，主要用于在-C上引入苯甲酰基。上引入苯甲酰基。(4) 苯甲酸酯苯甲酸酯COOC2H5+H CH2COC2H5OEtONaCOCH2COC2H5OH2OH2C CO2EtH2C CO2Et+CO2EtCO2EtNaOEtHCCO2EtH2CCO2EtCNCO2C2H5+NCCHCO2EtCH2CH3NaHCO2EtOOCH3(CH2)2CO2Eteg 1. 选用合适原料制备选用合适原料制备eg 2. 选用合适的原料制备选用合适的原料制备合成二：合成二：HCOOEt + C6H5CH2COOEtEtONa7

6、0%C6H5CHCOOEtCHOC6H5CHCOOEtCHOC6H5CHCOOEtCOOEt合成一：合成一：C6H5CHCOOEtCCOOEtOEtOOC-COOEt + C6H5CH2COOEtEtONa-CO175oCC6H5CHCOOEtCOOEt+ C6H5CH2COOEtEtONaC6H5CHCOOEtCOOEtOC2H5O-C-OC2H5合成：合成：eg 3. 选用合适的原料合成选用合适的原料合成OHO2C-CH2CH2CCOOH逆合成分析逆合成分析OHO2C-CH2CH2CCOOHOHO2C-CH2CH-CCOOHCOOHCOOEtEtO2C-CH2EtO2C-CH2COOEt+

7、EtO2C-CH-CCOOEtEtO2C-CH2O-CO2EtO-H+H+OH-HO2C-CH-CCOOHHO2C-CH2OHO2C-CH2CH2-CCOOHOeg 4. 选用合适的原料合成选用合适的原料合成逆合成剖析：逆合成剖析：具体合成：具体合成：CO2EtCO2EtCO2EtCO2EtCO2EtOCO2EtONaOC2H5CO2EtONaH+CO2EtONaH+（ 化化学学计计量量）NaOC2H5CH2CH2CO2C2H5NCH2CH2CO2H2H5H3CHClNCO2C2H5OH3CHClNaOC2H5（ 化化学学计计量量）（ 化化学学计计量量）CO2EtCO2EtCO2EtONaOC

8、2H5RRCO2EtORNaOC2H5CO2EtORNaOC2H5CO2C2H5C2H5O2CCH3CO2C2H5NaHOCH3C2H5O2CCO2C2H5H+CO2EtORCO2EtCO2EtRCOOEtORCO2C2H5OCD3I / t-BuOKCO2C2H5OD3C烷烷基基化化CO2C2H5OCD3重重排排NaOC2H5CO2C2H5OKt-BuOKCD3ICO2C2H5OCO2C2H5OCD3CRCHOOC2H5COOC2H5CHRHBRCOLCOOC2H5RCOCHRLLCOOC2H5RCOCHRCOOC2H5RCOCHRCH2CO2C2H5强强碱碱RCOClR或或RCOORCOC

9、H2COC2H5OHCH2CCH3OHpKa2024实例实例 2实例实例 3发生分子内酮酯缩合时发生分子内酮酯缩合时, 总是倾向于形成五元环、六元环。总是倾向于形成五元环、六元环。OOCH3CH2C-CH2CH2CH2-COC2H5+1 C2H5O-2 H3OOOCH3实例实例 1练习：拟定合理的反应机理练习：拟定合理的反应机理RCOEtORCH CRORCOCHCRORH+OEtHOEt烯醇式的特征：烯醇式的特征：IR: 有有OH吸收峰，吸收峰，1H NMR: 有有OH和烯质子信号，和烯质子信号， 化学试验：化学试验：与与FeCl3显色显色COCOCHHCCORORCOCORORCORCOH

10、+abaCCORHROORCOb+CCORRCOCORORCRCOH+abaCCORHRORCOb+CH3(CH2)3CCH2CH2CH3OCHCOC2H5OabCH3(CH2)3CO2C2H52aCH3(CH2)3CCH2CH2CH3OCH2CO+bOC2H5C2H5OabOCO2C2H5a+COOOC2H5C2H5ObCOOC2H5CO2C2H5NCO2C2H5OH3CabaNOH3C+COOC2H5C2H5OorNH2H3CH3CH3CO+2 HCHO+NH2H3CO+bNCOOC2H5CO2C2H5H3CNH2H3CCH2CCO2C2H5+2HH3CH3COEtO2COabcdaH3C

11、H3COO+COOC2H5C2H5OEtOOCH3CH3COEtO2CbCH3COEtH3CH3COEtO2COcdOC2H5H3CH3COEtO2CCH3OCCORCCORRXCCORR强强碱碱HCCOROHCCORORXCCOROR强强碱碱第一步若不采用强碱和低温，酮将不能完全烯第一步若不采用强碱和低温，酮将不能完全烯醇负离子化，会发生醇醛缩合等副反应。醇负离子化，会发生醇醛缩合等副反应。OCH3O强强碱碱 / / 低低温温ONaCH3I如如：NaNH2, LDA, NaH, Ph3CNa等等CO2EtLDA / -78oCCLiOOEtCH3IEtO2CCH3OCH3碱OCH3OCH3+

12、R XR XOCH3ROCH3RCOCCOCOCOCHBRXCOCCORCOCCHNCNCCHNArCCHNCCOCHCORCORORXCCORCOCCORRBrH3CCH3O强强碱碱H3CCH2O低低温温H3CCH2ORH3COC2H5OONaOEtH3COC2H5OOR(1) 稀稀OHH3COHOOR(2) H+,H3CCH2ORRBrCO2 H3COC2H5OONaOEt(1) 稀 OH(2) H+,H3CORR XH3COC2H5OOR H3CORH3COC2H5OORRRRXNaOEt(1) 稀 OH(2) H+, 2NaOEt(1) 稀 OH(2) H+,H3COH3COH3COH

13、3COCO2EtCO2EtI2H3COC2H5OO H3COEtOONaOEtH3COEtOOIH3COEtOOIIX(CH2)nXn = 0X2H3COC2H5OONaOEtRXXX(CH2)nNaOEt(1) 稀 OH(2) H+,?H3COC2H5OONaOEtRXNaOEt(1) 稀 OH(2) H+,?I2 2 2 2 2 NaOEtH3COC2H5OOBrCH2CO2Et(1) 稀 OH(2) H+, ?H3COC2H5OOROClNaHH3COC2H5OORO(1) 稀 OH(2) H+,H3CORONaHRXH3COROR (1) 稀 OH(2) H+,H3CCH2ORH3CO

14、C2H5OOR(1) 浓 OH(2) H+,H3COH2COHOROH+ H3COC2H5OORO(CH2)nH3COC2H5OOH3COC2H5OOH3COC2H5OORRH3COC2H5OO(CH2)nEtOOEtOONaOEt(1) OH(2) H+,OHORR XEtOOEtOORHOOHOOR- -CO2 H+H3COEtOH2COEtOR X(1)(2)OHOR强强碱碱RXNaOEt(2) H+, (1) OHOHOREtOOEtOORRRNaOEt(2) H+,R X EtOOEtOO(1) OHOHOREtOOEtOOREtOOEtOONaOEtXX(CH2)nHOO(CH2)

15、n(1) OH(2) H+, 2XX(CH2)nNaOEtEtOOEtOO(1) OH(2) H+,(CH2)nHOOHOO或 I2 HOOHOONaOEtEtOOEtOO(1) OH(2) H+,RNaOEtEtOOEtOORRBrCH2CO2EtXEtOOEtOOROEtONaOEtEtOOEtOORNaOEt 2?XXX(CH2)n或 I2 2 By using two molar equivalents of malonate anion and a dihalide, the dicarboxylic acid is obtainedC2H5XCC2H5H3C(H2C)3COOEtH

16、3C(H2C)3X+H2CCOOEtCOOEtCOOEtH2CCOOEtCOOEt(CH2)3CH3XNaOEtNaOEtC2H5X(1) OH(2) H+,CHCOOEtCOOEtC2H5CHCOOHH3C(H2C)3C2H5CCOOEtCOOEtH3C(H2C)3C2H5 CHCOOHH3C(H2C)3C2H5CH3OEtO2CI2NaOEtOCH3OCH3EtO2CEtO2C(1) 稀OH(2) H+,OCH3OCH3OCH3 OH2 OCH3OCH3OCH3OCH3OCH3EtO2CEtO2CCH3OCO2Et2+ I2OCH3OCH3OCH3CH3OEtO2COCH3OCH3EtO2

17、COCH3X+H3CCH2OC2H5OOC2H5OCH2OC2H5OOH3CCH3OC2H5OCH3OEg 1: 以乙酸乙酯为原料合成以乙酸乙酯为原料合成4-苯基苯基-2-丁酮丁酮CH3CCHCOOC2H5ONa+CH3CCHCOOC2H5OCH2C6H5CH3CCHCOOHOCH2C6H5CH3CCH2CH2C6H5OCH3COOC2H5RONa (1mol)C6H5CH2Cl1 稀稀OH -2 H+-CO2CH3CCH2CH2C6H5OEg 2: 选用不超过选用不超过4个碳的合适原料制备个碳的合适原料制备CH3CCHCOOC2H5O(CH2)4BrBrCH3CCCOOC2H5O2 CH3C

18、OOC2H5C2H5ONaCH3CCHCOOC2H5ONa+C2H5ONaCH3COCOOC2H5CH3COCOOHBr(CH2)4Br分子内的亲核取代分子内的亲核取代 稀稀-OHH+-CO2CCH3OCCH3O吡喃衍生物吡喃衍生物（主要产物）（主要产物）Eg 3: 乙酰乙酸乙酯与乙酰乙酸乙酯与BrCH2CH2CH2Br在醇钠作用下反应，在醇钠作用下反应， 主要得到主要得到 而不是而不是 。请解释原因。请解释原因。OCOOC2H5H3CCOCH3COOC2H5CH3CCH2COEtOOEtO-Br(CH2)3BrCH3CCHCOEtOOEtO-CH2CH2CH2Br有张力有张力CH3CEtO2

19、COCH3COOH-H+无张力无张力OCO2EtOH-H+OCO2HBrCO2EtOEg 4: 制备制备 CH3C-C-COOEtOCH3CH2CH2CH3CH3CH2CH2CHCOOHCH3CH3CH2CH2CHCOOHCH3H+NaOEtEtOHNaOEtEtOHCH3ICH3CH2CH2BrOH-（浓）（浓）+ CH3COOH酸式分解酸式分解CH3CCH2COOEtOEg 5: 选用合适的原料制备下列结构的化合物选用合适的原料制备下列结构的化合物。CH3CCH2CH2CH2COHOOCH3CCH2CH2CH2CCH3OOEg 6: 如何实现下列转换如何实现下列转换OLiCH3OCH3CH

20、OOCH3CHOOSi(CH3)3CH3OCH3OHCH3OHCH3+(CH3)3SiCl蒸馏分离蒸馏分离1mol n-C4H9BrCH3Lin-C4H9BrOCH3C2H5ONaHCOOC2H5(2mol) KNH2NH3(l)OH-引入醛基引入醛基的目的是的目的是帮助定向。帮助定向。 -烷基化烷基化n-C4H9CH3On-C4H9CH3OCHOn-C4H9CH3On-C4H9CH3CH3OOEg 7: 如何实现下列转换如何实现下列转换OOCH3CH3合成一：合成一：合成二：合成二：OCH3CH3NCH3N+OCH3OCH3NH+对甲苯磺酸对甲苯磺酸BrH3O+OCH3LDATHF -70o

21、CBrOCH3*1. 引入醛基的目的是为了使反应能定向进行。引入醛基的目的是为了使反应能定向进行。*2. 若若-二羰基化合物中的一个羰基是醛基，则在稀碱二羰基化合物中的一个羰基是醛基，则在稀碱 存在下，也能发生酮式分解。存在下，也能发生酮式分解。合成三：合成三：OCH3CHOOCH3CHOOCH3OCH3CHOBrOCH3C2H5ONaHCOOC2H51mol KNH2NH3(l)OCH3CHOOH-OCH3C-HOHO-CO2 + H2OCH3OCH3+ HCOOH-ROHOH-ROHCH2(CO2Et)22EtO-EtOHBrCH2(CH2)nCH2BrOH-H+-CO2SOCl2CH2(

22、CO2Et)22EtO-Eg 8：合成螺环化合物：合成螺环化合物还原还原I2在在 eg 9中的作用中的作用2 CH2(CO2Et)22 EtO-BrCH2CH2CH2BrCH(CO2Et)2CH(CO2Et)22 EtO-COOHCOOHH+I2OH-Eg 9： 用简单的有机原料合成用简单的有机原料合成COOHCOOH(COOEt)2(COOEt)2CH3CHO + 3CH2OCO2HHO2C2 CH2(COOEt)2 +BrBrBrBrCO2EtCO2EtEtO2CEtO2C(螺环二元羧酸螺环二元羧酸)CO2HHO2C(HOCH2)3C-CHOOHHOOHHOBrBrBrBr-CO2EtO-

23、HO-H+HO-HO-HBrEg 10 用简单的有机原料合成用简单的有机原料合成浓浓OOOOEg 11 用简单的有机原料合成用简单的有机原料合成CH2(CO2Et)2EtO-O分子内酯交换分子内酯交换EtO-分子内酯交换分子内酯交换OOR1R2OR1R2XX+OR1X(1) LDA / 低温(2)OR1(1) LDA / 低温(2)R2XOR1R2OR1R2（少少量量）+OR1OR1X+bOEtOOEtR1X+OR1CO2EtOCO2Eta重重排排R2XOR1CO2EtOCO2EtR1XOR1R2CO2Et(1) 稀 NaOH(2) H+,OR1R2NaOEtOR1CO2EtNaOEtt-Bu

24、OK O(1) LDA / 低低温温(2)OR1R2XR1XOR1CO2EtOR1R2CO2Et(1) 稀 NaOH(2) H+,OR1R2 NaOEtOEtOOEt1. NaH 2.NCO2C2H5OH3CbNCOOC2H5CO2C2H5H3CNH2H3CCH2CCO2C2H5+2HEtOCHOOEtOOOCH3+CH2CHCH2CH2CHCH2XCH3X+CH3aEtOOOOEt+CH3CH2CO2EtEtOCOOCH2CHCH2CO2EtCH3EtOCHOOCO2EtCH3+CH2CHCH2Xb EtOOOOEt+CH3CH2CO2EtNaOEtEtOOOCO2EtCH3NaOEtXEt

25、OOOCH2CHCH2CO2EtCH3(1) 稀 OH(2) H+,HOOOCH2CHCH2CH3EtOOOCH2CHCH2CH3酯酯化化CHCOCCOHRX碱碱CRCOCCOHRXCHCOCCOR 碱碱RXCH2COH3CCCH3O CHCONaH2CCCH3ONaCH2COCH2CCH3ORNH4ClRCOXNH4ClCH2COCH2CCH3ORCO2 NaNH2or 用用RLi，惰性溶剂，惰性溶剂NH3(液液)CH3CCH2COC2H5OONaNH2CH3CCHCOC2H5OONa+NaNH2NH3(液液)1mol RX1mol RX1mol RCOX1mol RCOX1mol 1mol

26、 RCOOEtRCOCRO ONH4Cl or H2O乙酰乙酸乙酯的乙酰乙酸乙酯的-烷基化、烷基化、-酰基化酰基化（小结）（小结）Some Biological Carbonyl Condensation ReactionsMalonyl ACP is decarboxylated and enolate is formedEnolate is added to the carbonyl group of another acyl group through a thioester linkage to a synthaseTetrahedral intermediate gives acet

27、oacetyl ACPCCOCCCOCCCOHCCOH+碱碱CCOCCCOCCCOBCCOHB BHOOORXOOROO+OO碱碱 or 酸酸O碱碱碱碱RO碱碱CH3OOOEtabOOCH3OOH3CH3COEt+H3COOEtH3COCH32abCH3O+H3COCH3+H3COOEtOH3CH3COEtH3COCH3CH3OOOEtabCH3OOOEt12345EtO2CCH3OOOEt12345EtO2CCH3C2H5OOO12OC2H5O345H3CH3CCH3OC2H5OOC2H5OO45321CH3H3COH3CH3CH3COBrCH2OOEtCH3OOH3CH3CEtO2COH稀

28、稀H+OOH3CH3CBrZnCH2OOEtZnOH3CH3COEtOH3CH3COEtOHCO2EtNaOEtOEtCO2EtOOH3CH3CAl2O3NaOEt OOOabaO+ObH3COCH3O+OOOaOOEtO2CO+OEtO2COOEtO2COCH3EtO2CO+bH2SO4CH3CH3OOCH3CH3OCH3H3COCH3CH3COOEtEtOOEtOEtO2CCH3CH3OCH3OEtMe3NOCH3CH3OCH3EtO2C主要产物主要产物(1)(2)+H3CH3CCO2EtOCO2EtOOCO2EtOOXBrONaOEtor NaHH3CCO2EtOCO2EtOONaOEt

29、HOEtCO2EtOOOCH2O+OXOOCH2OO+OOROO+OOOOORO+OOO+OOOPhPhOOH3CH3COC2H5OOC2H5OONaOC2H5CH3OOOEtEtO2COOEtO2CNaOEtOH稀稀H+OOMichael加加成成NaOEtCH3IOOCH3H3CON(CH3)2或或 OOOOOCH3OH3COH3COKOH 或 NaOEtKOH或 NaOEtOHH2OOOOOOHHOOOOOHHOOOOH2COOHOOOOHHOHOOOHPhCOCHRHOEtPhCOCHRPhOOEtOCPhRPhOOEtOEtHOPhRPhOEtOOPhRPhOOEtEtOHOPhRPh

30、OOEtOPhRPhOOEtOPhRPhO+OEtCH2OHNH2CH2OOOOOOOOOOHSOOH3CH3CCHO+H3CH3CCO2EtCO2EtNH+H2OCH2(CO2Et)2 Ar CHO+RCH2COONaArCOOHHR(RCH2CO)2O Ph CHO+H3COCH3OOCH3COONaPhCOOH H2COCH3OOHOAcH2COCH3OOPh CHOOCH3OOPhCHOOCH3OOPhOOCH3OOPhOHOAcOOPh+CH3OOCH3COONaOHCHO(CH3CO)2OOOCH3COONaCHO(CH3CO)2OOOHNiOOHor HFPPAOH2RROXCH

31、CO2EtR+ORRCO2EtREtONaEtOXCRHCOEtOXCRCOEtORROXCRCOEtORCROORRCO2EtR(CH3)2C=O +CH2CO2EtCH2CO2EtNaOC2H5(CH3)2C=CCH2CO2-CO2EtH+(CH3)2C=CCH2CO2HCO2Ett-C4H9OK, t-C4H9OHPh2CO +CH2CO2EtCH2CO2EtH+Ph2C=CCH2CO2HCO2Et90%94%RO-CH2CH2CO2Et CO2EtCH2-CHCO2Et CO2EtC ORRCO-RRCH CH2CO2EtCOOEtCORRCHCOEtO-CH2CO2EtCORRCCC

32、H2CO2EtOHRO-(1)CH2CO2-CO2Et(2)RRCCCCH2CO2HCO2EtCRRCHCRRCH2CO2HH+/H2O, -CO2CHO(CH2COOEt)2CH=CCOOEtCH2COOHNaOC2H5H3O+CH=CCOOHCH2COOH- CO2HCCHCH2HO2C催化剂HH2CCH2CH2HO2CPPAO75%80%CCHO+CCNR2Hor OHRHNR2RCCNRCCNROCCNROH+OH+R2NHHO+NHR2H+HONR2H+H2ONR2+H2ONR2+NR2+HHNR2+H+CCNR2RCCNR2RCCORCCORRX1.2. H2O / H+CCORR

33、COCl1.2.CCCORORO1.2.ROCOH2O / H+H2O / H+RRR CCNR2RC=C-NC-C=N+O+NHH+N+N使用活泼卤代烷如碘甲烷、烯丙型卤化物、使用活泼卤代烷如碘甲烷、烯丙型卤化物、苯甲型卤代物等主要生苯甲型卤代物等主要生成成碳烃基化产物。碳烃基化产物。ONHH+N(1)Br(2) H3O+O(1) CH3COCl(2) H3O+OCH3OH3CO2CONH+(1)(2) H3O+CH3H3CBrOH3CO2COCH3CH3OH3CO2CNHOH3CNHH+H3CNCH3O(1),(2) HOAc, NaOAc, H2O,OH3COH3CH3CO OH3CCH

34、3ONaOC2H5OH3COCH3(1) NaOH/H2O(2) H+, H3CONBrNH2ONOH2NOHHOH+NHO+NHHNNBrHHNHNBrH2O, H+H3CNCH3OOH3COH3CH3CONH2O / HH3COCH3HNH3COCH3HNHORNRNR90%H+ORR(1) R-X(2) H3O+HH碱碱 R-XORR热热力力学学控控制制条条件件下下OROROOCH2CH2COOCH3OCH2CH2COOCH3CH3OOCCH2CH2NHNC2H5OH+H+CH2=CH-COOCH3H3O+2CH2=CH-COOCH3H3O+二氧六环二氧六环EtOOEtOH3COHCEt

35、OOEtO1 2345345H3COOHCEtOO12345+Et345EtOOEtOOHCEtOOEt+12345CHOMeOO碱碱CO2MeOHCEt碱碱H3COMeO2COHCEtH3COH+MeOOEtONO+ ClC(CH2)8CClOOO(C2H5)3NH3O+OOOH3O+OH-OOOOHOOHZn(Hg) HClHOOC(CH2)20COOHGilbert Stork, developed enamine chemistry and also did a total synthesis of Quinine ( Born 1921,12,31 )C & E News, 26 Feb, 2007NXOH2O / HOOCH3CH3NCO2CH3H3CO2C+NCH3CH3H3CO2CCO2CH3(1)(2)NXONOHXNONOH2ONOOH2NHOOHOHOOONH+NH2+CH3CH3NCCO2CH3NCH3CH3H3CO2CCO2CH3H3COOCH3CH3NCCO2CH3H3COOR2CHX+SN2Ph3PCR2HBPh3PCR2Ph3PCR2XPh3P- -HBPh3P CH2Ph XPh3P CH2CO2Et XNaOEt