在强碱作用下酯缩合的反应机制 0) CH2CHCO2C2HsCCH3CCO2CH OCH3 QCH3 CH3CHCCCOCCHaCHCC-COCs C2H5O CH3 CH3 OCH3 PCNa (CH3)2C-C-C-CO2C2Hs PhaCH CH3 ↓o OCH3 (CH3)2CHC-C-CO2C2Hs CH3