Enantioselective conjugate additions of silylketene acetals to 2-carboxycyclopentenones promoted by chiral Ti complexes

被引：51

作者：

Bernardi, A

Karamfilova, K

Sanguinetti, S

Scolastico, C

机构：

[1] Dipto. di Chim. Organ. e Industriale, Ctro. CNR Stud. delle Sostanze O., 20133 Milano

来源：

TETRAHEDRON | 1997年 / 53卷 / 38期

关键词：

D O I：

10.1016/S0040-4020(97)00825-9

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The conjugate addition of silylketeneacetals to 2-carbalkoxycyclopentenones 1 promoted by TADDOL . TiCl2 complexes was studied. The reactions are highly syn selective. The enantioselectivity depends on the size of the substrate ester group, with the methyl ester 1b being more enantioselective than the ethyl ester 1a. E.c. up to 47% are achieved. The absolute configuration of the major product was established by chemical correlation to the known (+)-isodchydroiridodiol. The reaction of representative doubly activated alkenes was studied: good results were obtained with cyclopentenones and gamma-butenolides. (C) 1997 Published by Elsevier Science Ltd.

引用

页码：13009 / 13026

页数：18

共 103 条

[1]

ALDERDICE M, 1984, ORG SYNTH, V62, P14

[2] ASYMMETRIC MICHAEL REACTION USING MACROCYCLIC LACTOSE DERIVATIVES AS CHIRAL CATALYSTS [J].