Synthesis of the Oudemansins, Naturally Occurring β-Methoxyacrylates From Basidomycetes

Short, stereocontrolled syntheses of the antifungal metabolites oudemansins A (1) and B (2) from a common precursor (5) are described. Stereospecific olefination of 5 via the β-keto phosphine oxides 12 and 21 affords dienes (E)-7 and (E)-22, which are transformed to the corresponding styryl esters 14 and 23. Introduction of the β-methoxyacrylate group by acylation of 14 and 23 with N-formylimidazole affords the title compounds exclusively.