Enantioselective synthesis of 5-substituted α,β-unsaturated δ-lactones:: application to the synthesis of styryllactones

A flexible enantioselective synthesis of highly functionalized 5-substituted alpha,beta-unsaturated delta-lactones has been achieved by applying the Sharpless catalytic asymmetric dihydroxylation to vinylfuran as the key step. The resulting diols are produced in high enantio excess and can be stereoselectively transformed into differentially protected delta-lactones through a short reaction sequence. (C) 1999 Elsevier Science Ltd. All rights reserved.