Selective synthesis of optically active 3-haloazetidin-2-ones or aziridines by the condensation of various metal enolates of α-haloacetate with a chiral imine
作者:Tamotsu Fujisawa、Ryuuichirou Hayakawa、Makoto Shimizu
DOI:10.1016/s0040-4039(00)74774-5
日期:1992.12
Reaction products and their diastereofacial selectivity in the condensation of the ester enolates of α-haloacetate with a chiral imine possessing 1,3-dioxolane ring derived from (2S,3S)-1,4-dimethoxy-2,3-butanediol as a chiral auxiliary can be fully controlled by the metal enolate used; i.e., (3R,4R)-3-haloazetidine-2-one is obtained stereoselectively by the use of the triisopropoxytitanium enolates
α-卤代乙酸酯的烯醇酯与具有由(2 S,3 S)-1,4-二甲氧基-2,3-丁二醇衍生的具有1,3-二氧戊环的手性亚胺缩合的反应产物及其非对映选择性所用的金属烯醇化物可以完全控制手性助剂;即,(3 R,4 R)-3-卤氮杂环丁烷-2-酮是通过使用三异丙氧基钛烯醇盐立体选择性地获得的,而与锂或锌烯醇盐的缩合可提供(2 R,3 S)-或(2 S, 3 R)-氮丙啶。