用铝-镍合金还原1-萘酚反应的再研究

Reinvestigation of the Reduction of 1-Naphthol Using Ni-Al Alloy

文献曾报道以铝-镍合金为还原剂,在稀碱水溶液中,可以将1-萘酚(1)以高收率还原为5,6,7,8-四氢-1-萘酚(2).本研究工作发现,在相同的条件下该反应除了生成少量2外,3,4-二氢-2H-萘-1-酮(3)和1,2,3,4-四氢-1-萘酚(4)为主要产物,该结果明显不同于文献报道,对反应产物分布及其可能机理进行了探讨.该还原反应体系为3,4-二氢-1(2H)-萘酮(3)和1,2,3,4-四氢-1-萘酚(4)的合成提供了一条新途径.

The reduction of 1-naphthol （1） in dilute aqueous KOH using Ni-Al alloy as a reducing agent reported in the literature gave 5,6,7,8-tetrahydro-1-naphthol （2） in a high yield. The reinvestigation of this reaction under the same experimental conditions disclosed that the major products were 3,4-dihydro-2H- naphthalen-1-one （3） and 1,2,3,4-tetrahydro-1-naphthol （4） besides the formation of 2 as the minor product. The product distribution was examined and the possible mechanism was proposed. Accordingly, the reduction of 1-naphthol using Ni-Al alloy under alkaline conditions has provided a new synthetic pathway for the preparation of 3 and 4.