ALPHA'-BENZOYLOXY AND ALPHA'-METHOXYMETHOXY LITHIUM ENOLATES GIVING OPPOSITE DIASTEREOFACIAL SELECTIVITIES IN ALDOL REACTIONS - USE OF (PROBABLE) EXTENDED CHELATION FOR REVERSAL OF STEREOSELECTIVITIES

被引：16

作者：

CHOUDHURY, A ^{[1
]}

THORNTON, ER ^{[1
]}

机构：

[1] UNIV PENN,DEPT CHEM,PHILADELPHIA,PA 19104

来源：

TETRAHEDRON LETTERS | 1993年 / 34卷 / 14期

基金：

美国国家卫生研究院;

关键词：

ALDOL; LITHIUM ENOLATE; CHELATION; NONCHELATION; HIGH FACIAL SELECTIVITY;

D O I：

10.1016/S0040-4039(00)77578-2

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The Li enolates of alpha-benzoyloxy and alpha-methoxymethoxy ketones 1a and 1c afford nonchelation and chelation aldol products, respectively, both with usefully high diastereofacial selectivities. Evidence suggests that transition state chelation of the benzoyl C=O is responsible for the observed ''nonchelation'' stereoselectivity of 1a.

引用

页码：2221 / 2224

页数：4

共 25 条

[1] HIGH DIASTEREOFACE SELECTION IN AN ESTER ENOLATE ADDITION TO ALPHA-ALKOXY ALDEHYDES - STEREOSELECTIVE SYNTHESIS OF ALPHA-METHYLENE-BETA-HYDROXY-GAMMA-ALKOXY ESTERS [J].