Addition of alkyl or aryl α-substituted acetophenones to N-methylisatin in basic media gives diastereomeric mixtures of the corresponding α-substituted 3-benzoylmethyl-3-hydroxy-1-methyloxindole in good yields. Under anhydrous conditions (concentrated sulfuric acid at 0 °C) these adducts eliminate benzoic acid, instead of water, to give pure (E)-3-alkylidene derivatives in quantitative yield. Applying the same treatment to the α-unsubstituted analogue, dehydration took place to give pure (Z)-3-benzoylmethylen-1-methyloxindole.
在碱性介质中,将烷基或芳基取代的α-取代
乙酰苯加入到N-甲基亚苄基中,可得到相应α-取代的3-苯甲酰甲基-3-羟基-
1-甲基吲哚的非对映异构体混合物,产率良好。在无
水条件下(0°C时的浓
硫酸),这些加合物消除
苯甲酸而非
水,以定量产率得到纯的(E)-3-亚烷基衍
生物。对α-未取代的类似物施以相同处理,脱
水反应得到纯的(Z)-3-苯甲酰亚甲基-
1-甲基吲哚。