B CH3CH2C-CH2 CH3 CH3 NaOH CH.CH2CCH 次要产物 29/% B B 乙醇，△ Br CH3CH-CCH3 CH3 主要产物71% 查依采夫(Saytzeff)规则：主要产物是双 键碳上连有最多取代基的烯烃。次要产物 29% 主要产物 71% CH3 CH2 CCH3 Br CH3 NaOH 乙醇, CH3 CH2 C=CH2 CH3 CH3 CH CCH3 CH3 β β β 查依采夫(Saytzeff)规则：主要产物是双 键碳上连有最多取代基的烯烃