Stereoselective synthesis of sugar allenes and their hydrosilylation catalyzed by biscobaltoctacarbonyl

Stereoselective introduction of allenyl group to glycals has been developed with propargyltrimethylsilane under the catalysis of a Lewis acid to produce largely the a-sugar allenes in good yields. The subsequent hydrosilylations of these sugar allenes were catalyzed by biscobaltoctacarbonyl to obtain the corresponding vinylsilanes. Stereochemical selectivity is also discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.