An enantioselective total synthesis of phomopsolide C

A flexible enantioselective route to highly functionalized alpha,beta-unsaturated delta-lactones, has allowed for the synthesis of phomopsolide C. This approach derives its asymmetry from (S)-lactic acid and by applying the Sharpless catalytic asymmetric dihydroxylation to vinylfuran. The resulting diols are produced in high enantioexcess and can be stereoselectively transformed into alpha,beta-unsaturated-delta-lactones via a short highly diastereoselective oxidation and reduction sequence. A Wittig olefination reaction was used to introduce the side chain in either cis or trans form that was further elaborated into phomopsolide C. (C) 2002 Published by Elsevier Science Ltd.