Oxidative degradations of the side chain of unsaturated Ent-labdanes. Part I

Abstract

A selective route for the degradation of the unsaturated side chain of ent-labdanes has been devised, giving two useful synthons: 2β-acetoxy-14, 15,17-trinor-ent-labdane-8,13-dione (5) and 2β-acetoxy-14,15-dinor-ent- labd-8(17)-en-13-one (7), the use of which for the preparation of terpenylquinone derivatives shall be reported elsewhere.