Synthesis and Anionically Induced Domino Reactions of Chiral α-Bromo α,β-Unsaturated Esters
作者:Norbert A. Braun、Ulrike Bürkle、Martin P. Feth、Iris Klein、Dietrich Spitzner
DOI:10.1002/(sici)1099-0690(199808)1998:8<1569::aid-ejoc1569>3.0.co;2-w
日期:1998.8
The chiral α-bromo α,β-unsaturated esters 3 and 9 are prepared by asymmetric Sharpless dihydroxylation (AD) of 5 and from ester 7 and the chiral diols 8 by transacetalization, respectively. Both types of α-bromo α,β-unsaturated ester react with the kinetic lithium dienolates of enone 10 to give functionalized tricyclo[3.2.1.02,7]octanes 11. Esters 3 give one single diastereomer (de ≥ 95%), whereas
手性 α-溴 α,β-不饱和酯 3 和 9 分别通过 5 的不对称 Sharpless 二羟基化 (AD) 和酯 7 和手性二醇 8 通过转缩醛化制备。两种类型的 α-溴 α,β-不饱和酯与烯酮 10 的动力学二烯醇锂反应生成官能化的三环 [3.2.1.02,7] 辛烷 11。酯 3 生成一种单一的非对映异构体(de ≥ 95%),而混合物的非对映异构体(de 28 至 46%)与酯 9 一起获得。