Reversal of stereoselectivity in the Evans aldol reaction of alpha,alpha-difluoro and alpha,alpha,alpha-trifluoro carbonyl compounds

被引：38

作者：

Iseki, K

Oishi, S

Kobayashi, Y

机构：

[1] MEC Laboratory, Daikin Industries Ltd., Miyukigaoka, Tsukuba

来源：

TETRAHEDRON | 1996年 / 52卷 / 01期

关键词：

D O I：

10.1016/0040-4020(95)00858-6

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The Evans aldol reaction of hexafluoroacetone and trifluoroacetaldehyde causes complete reversal of diastereofacial selectivity. The boron enolate derived from N-acyloxazolidinone 2 reacts with trifluoroacetaldehyde to give anti and ''non-Evans'' syn aldols with stereoselectivity in the range of 7:3-17:3. With alpha,alpha-difluoroaldehyde 4b, a small amount of the normal syn aldol was formed. However, the anti aldol was the major product.

引用

页码：71 / 84

页数：14

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