Validating an endoperoxide as a key intermediate in the biosynthesis of elysiapyrones

Abstract

Compounds 1-3 isolated from Elysia diomedea are described. Compound 1 is an endoperoxide derivative of elysiapyrone A. The biomimetictype transformation of compound 1 to elysiapyrone A catalyzed by neutral base transformed the endoperoxide to a vicinal diepoxide, thus suggesting the endoperoxide as a key intermediate in the biosynthesis of elysiapyrone A. A biogenetic pathway for their formation involving a cycloaddition of singlet oxygen to a polypropionate alkenyl open chain is proposed.