Preparation of optically active alpha-silylcarbonyl compounds using asymmetric alkylation of alpha-silylacetic esters and asymmetric metal-carbene insertion into the Si-H bond.

Substituted alpha-silylacetic esters have been prepared in good yields and with reasonable diastereoselectivities by three different routes. The first two involved alkylation of the parent alpha-silylacetic ester enolates, with the chiral auxiliaries being present either on silicon or on the ester function. The third route involving asymmetric insertion of metal-carbenoids into the Si-H bond was found to afford better diastereoselectivities, using pantolactone as chiral auxiliary. (C) 1997 Elsevier Science Ltd.