作者:Masaki Yamada、Kazuya Nakao、Toshio Fukui、Ken-ichi Nunami
DOI:10.1016/0040-4020(96)00209-8
日期:1996.4
Stereoselective β-bromination ofN-formyl-α, β-dehydroamino acid esters5 was investigated. A reaction of5 with NBS affordedα-bromo-N-formylimines10 which successively isomerized to giveβ-bromo-N-formyl-α, β-dehydroamino acid esters4. The migration of the double bond of the intermediates10 with bulky substituents at the β-position resulted in highly stereoselective formation of(Z)-4, while that of the
研究了N-甲酰基-α,β-脱氢氨基酸酯5的立体选择性β-溴化。5与NBS的反应得到α-溴-N-甲酰亚胺10,其连续异构化以得到β-溴-N-甲酰-α,β-脱氢氨基酸酯4。具有在β位的大取代基的中间体10的双键的迁移导致(Z)-4的高度立体选择性的形成,而具有大的取代基的底物的双键的非立体选择性地进行。在使用AM1进行半经验计算的基础上,提出了立体选择性溴化的机理。