Synthesis (in ent-form) of a novel jalcaguaianolide from Ferula arrigonii Bocchieri

Abstract

A recently isolated isodehydrocostus lactone from the genus Ferula(Umbelliferae) has been stereoselectively prepared in ent-form from α-santonin by photochemical transformation to O-acetylisophotosantonic lactone followed by functional group manipulations that conclude with a one-step γ-butyrolactone →Δ^α,β-butenolide conversion; the synthesis corroborates both the structure and the relative and absolute stereochemistry that have been proposed for the natural product.