Simple preparation of trans-epoxides via ylide intermediates

被引：10

作者：

Aggarwal, VK ^{[1
]}

Aragoncillo, C ^{[1
]}

Winn, CL ^{[1
]}

机构：

[1] Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England

来源：

SYNTHESIS-STUTTGART | 2005年 / 08期

关键词：

asymmetric catalysis; diazo compounds; epoxidations; sulfur ylides; epoxides;

D O I：

10.1055/s-2004-834885

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

A practical route to epoxides with control of the relative and absolute stereochemistry has been developed. allowing epoxides to be readily prepared on a 20 mmol scale by generating the reactive intermediate (the diazo compound) in situ from benzaldehyde tosylhydrazone sodium salt. In this paper. we describe the optimum conditions for three procedures to obtain the desired racemic and enantiomerically enriched epoxides (Scheme 1). High diastereoselectivities (98-100;) and very high yields of epoxide were obtained. Asymmetric epoxidation was carried out using the chiral camphor-derived [2.2.1] bicyclic sulfide 4 and the desired epoxide was obtained with excellent enantioselectivity (94%).

引用

页码：1378 / 1382

页数：5