An enantioselective synthesis of phomopsolide D

A short enantioselective route to the highly functionalized α,β-unsaturated δ-lactone natural product phomopsolide D and three of its stereoisomers, has been accomplished. All of the carbon atoms of phomopsolide D come from tiglic acid and 2-furyl-1-penta-1′,3′-dienylketone (furan plus hexadienal). This approach derives its asymmetry from the sequential use of two catalytic asymmetric reactions; these being a Sharpless dihydroxylation reaction and a Noyori furylketone reduction. The resulting furfuryl alcohols were stereoselectively transformed into α,β-unsaturated δ-lactones via a short highly diastereoselective oxidation and reduction sequence.