A stereodivergent construction of β-lactam skeletons via condensation of ester enolates and a chiral imine
作者:Tamotsu Fujisawa、Yutaka Ukaji、Tomohiro Noro、Kengo Date、Makoto Shimizu
DOI:10.1016/0040-4039(91)80535-e
日期:1991.12
an addition reaction of ester enolates to a chiral imine with 1,3-dioxolane, derived from (S,S)-1,4-dimethoxy-2,3-butanediol as a chiral auxiliary, could be fully regulated by the appropriate selection of metal enolates used. Addition of the lithium enolates provided (4S)-β-lactams, while the corresponding (4R)-β-lactams were obtained by the condensation of titanium enolates with the chiral imine.
酯烯醇酸酯与1,3-二氧戊环的手性亚胺的加成反应中的非对面选择性可以由(S,S)-1,4-二甲氧基-2,3-丁二醇作为手性助剂来调节。的金属烯醇化物适当选择使用。加入烯醇锂提供了(4S)-β-内酰胺,而相应的(4R)-β-内酰胺通过烯醇钛与手性亚胺的缩合获得。