吸电子基a一位上的H在碱存在下 转变成烯醇盐电子给体: LDA.THE ll H3C-C-CH3-H2C-C-CH3 H2C=C-CH3 LDA.THE H3C-C-OEt2 H2c-c-OEt2 H2C=C-oET Naot CH2(COoT )2 CH(COOEt )2 2 Naot H3C-C-CC-OEt C-C-OEt 或NaOH Organic chemOrganic Chem 吸电子基α－位上的 H 在碱存在下 转变成烯醇盐电子给体： H3C C CH3 O LDA,THF H2 C C CH3 O H2 C C CH3 O H3 C C OEt 2 O LDA,THF H2C C OEt 2 O H2 C C OET2 O CH2 (COOEt ) 2 NaOEt CH(COOEt ) 2 H3 C C H2 C O C OEt O NaOEt 或NaOH H3 C C H C O C OEt O