The meliacins (limonoids). Acid-catalysed reactions of meliacin epoxides

Abstract

Meliacin 14,15-epoxides in which ring D is a δ-lactone are stable to acid if C-7 carries an oxo- or an acetoxy-function. However, such compounds having a 7α- or 7 β-hydroxy-group undergo ready acid-catalysed rearrangements not hitherto observed. The 1,2-epoxy-3-oxo-system, in the absence of the 14,15-epoxide function, is slowly hydrolysed by acid to a diol. Structures have been assigned to the products of the rearrangement reactions.