The chemistry of pseudomonic acid. Part 3. The rearrangement of pseudomonic acid A in acid and basic solution

Abstract

The acid and base catalysed rearrangement products of pseudomonic acid A (1a), derived from (1a) by intramolecylar opening of the epoxide ring, have been shown to possess the trans-fused bicyclic structures (2a) and (3a). Structural assignments were made on the basis of the spectroscopic and chemical properties of (2a) and (3a) and their derivatives and confirmed by X-ray analysis. In strongly basic solution intramolecular rearrangement of (1a) was accompanied by the loss of the nonanoate ester side chain and formation of (12a) and (13a).