0 H00M00 0 00 C-cH 3C2s51--cH+G2HSOH ③交错的酯缩合反应: 151 H-C-OEt +Ch Ch COOEt (1) NaOEt H-C-CHCOOEt 甲酸酯,形-H Ch 152: EtO-C--C-OEt+ CH3CH2C0OEt (1)NaOEt CH CHCooEt 草酸酯,形-H (2)H C=0 00 COOT ≥CH3cH(cO0E)2O NaH O -C-H O + C2 H5 OH O -CH OC2 H5 O - + H-C-OC2 H5 O ③ 交错的酯缩合反应： 例1： H-C-OEt O + CH3 CH2 COOEt (1) NaOEt (2) H+ O H-C-CHCOOEt CH3 甲酸酯，无 -H  (1) NaOEt (2) H+ EtO-C--C-OEt + CH3 CH2 COOEt O O CH3 CHCOOEt COOEt C=O -CO  CH3 CH(COOEt)2 草酸酯，无 -H  例2：