羟醛缩合(10%NaOH)：CH3-CHO+CH3-CHO→CH3-CHOH-CH2-CHO

加热CH3-CHOH-CH2-CHO→CH3-CH＝CH-CHO

氧化：CH3-CH＝CH-CHO+[O]→CH3-CH＝CH-COOH