Tetrahedron

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

A Bernardi, K Karamfilova, S Sanguinetti, C Scolastico

Index: Bernardi, Anna; Karamfilova, Katia; Sanguinetti, Silvia; Scolastico, Carlo Tetrahedron, 1997 , vol. 53, # 38 p. 13009 - 13026

Full Text: HTML

Citation Number: 46

Abstract

The conjugate addition of silylketeneacetals to 2-carbalkoxycyclopentenones 1 promoted by TADDOL· TiCl2 complexes was studied. The reactions arc highly syn selective. The enantioselectivity depends on the size of the substrate ester group, with the methyl ester lb being more enantioselective than the ethyl ester la. Ee up to 47% are achieved. The absolute configuration of the major product was established by chemical correlation to the ...