Lipase-catalyzed conversions of trimethylsilyl ethers: deprotection, acetylation, epoxidation and one-pot-multi-step reactions

Unsaturated trimethylsilyl ethers are converted by lipase-catalyzed hydroly sis of ethyl acetate directly to alkenol acetates; the hydrolysis of diethy l carbonate yields unstable carbonic acid monoethylester, which deprotects trimethylsilyl ethers under mild conditions and without remaining acid. By the analogous lipase-catalyzed perhydrolysis of these esters with hydrogen peroxide, epoxyalkanol acetates and epoxyalkanols are obtained in one-pot r eactions with selectivities of 90-97%. Using longer chain peroxy fatty acid s, generated in-situ by lipase-catalyzed reaction of fatty acid and hydroge n peroxide, trimethylsilyl ethers are selectively (83-95%) epoxidized witho ut removal of the protecting trimethylsilyl group. (C) 1999 Elsevier Scienc e B.V. All rights reserved.