Practical Procedure for the Chemoselective Reduction of Esters by Sodium Borohydride. Effect of the Slow Addition of Methanol
作者:Kenso Soai、Hidekazu Oyamada、Masako Takase、Atushiro Ookawa
DOI:10.1246/bcsj.57.1948
日期:1984.7
achieve effective reduction. On the other hand, each individual solvent, methanol or t-butyl alcohol, was not effective for the reduction. The procedure provided a practical method for the functional group selective reduction of esters in the presence of chloro, cyano, carboxylato, carbamoyl, carboxy or nitro groups, which can not usually be performed by lithium aluminium hydride.
使用容易获得的硼氢化钠检查溶剂对酯还原的影响,该硼氢化钠已知不能还原此类官能团。在叔丁醇-甲醇或四氢呋喃-甲醇的混合溶剂中,发现各种羧酸酯和内酯被硼氢化钠以高产率还原为相应的醇或二醇。将甲醇缓慢添加到酯和硼氢化钠在叔丁醇或四氢呋喃中的回流混合物中对于实现有效还原是必不可少的。另一方面,每个单独的溶剂,甲醇或叔丁醇,对还原无效。该程序为在氯、氰基、羧基、氨基甲酰基、羧基或硝基存在下酯的官能团选择性还原提供了实用的方法,