20.4 The malonic ester synthesis Synthesis of substituted acetic acids acidic OCH2 CH3 CH3CH,, COOCHCH3 Diethyl malonate H oCH2CH 丙二酸二乙酯 NaoCH, CH3 CH3 CH,OH R—X OCH2CH3 R—X OCH2CH3 X(CH2)4X20.4 The Malonic ester synthesis: Synthesis of substituted acetic acids CH3CH2OCCH2COOCHCH3 O Diethyl malonate 丙 二 酸 二 乙 酯 O O O OCH2CH3 OCH2CH3 H H acidic O O OCH2CH3 OCH2CH3 H NaOCH2CH3 CH3CH2OH - Na R X + R X X(CH2 ) 4X