20.8 The knoevenagel condensation (N 诺温格缩合, Active hydrogen compounds condense with aldehydes and ketones known as Knoevenagel condensations these aldol-like condensations are catalyzed by weak bases an example is the following OCH2CH3 (CH3CH,N CH3 CH,OF H OCH2CH3 Diethyl malonate 丙二酸二乙酯 OCH2CH OCH2CH3 H,O CH OCH2 CH3 OCH2CH320.8 The knoevenagel condensation（克 诺温格缩合） Active hydrogen compounds condense with aldehydes and ketones known as Knoevenagel condensations, these aldol-like condensations are catalyzed by weak bases. An example is the following: Diethyl malonate 丙 二 酸 二 乙 酯 O O OCH2CH3 OCH2CH3 H H O H + (CH3CH2 )NH CH3CH2OH CH OH O O OCH2CH3 OCH2CH3 - H2O C H O O OCH2CH3 H OCH2CH3