作者:Stephen G. Davies、Alison J. Edwards、Iain A. S. Walters
DOI:10.1002/recl.19951140409
日期:——
enolates derived from the highly diastereoselective conjugate additions of lithium (R)-N-benzyl-N-α-methylbenzylamide (R)-1 to N, N-dimethyl crotonamide 2 and N, N-dimethyl cinnamide 3 have been investigated. The alkylations of enolates derived from 3 are shown to afford anti-α-alkyl-β-amino carboxamides with excellent stereocontrol: the stereochemistry is assigned with the aid of a single crystal X-ray structure
锂(R)-N-苄基-N-α-甲基苄基酰胺(R) -1与N,N-二甲基巴豆酰胺2和N,N-二甲基肉桂酰胺3的高度非对映选择性共轭加成反应得到的烯醇化物的烷基化反应已经完成。调查。已显示源自3的烯醇化物的烷基化可提供具有出色立体控制的抗α-烷基-β-氨基羧酰胺:借助(2R,3S,αR)-N的单晶X射线结构确定立体化学,N-二甲基2-苄基-3-苯基-3-(N-苄基-N-α-甲基苄基氨基)丙酰胺(2R,3S,αR-10。由于水解这些受阻的β-氨基酰胺(例如10)遇到的困难,因此开发了另一种方法,包括以α,β-不饱和N-酰基恶唑烷二-2-酮为底物进行共轭加成烷基化,从而得到选择性烷基化的产物易于还原裂解。