A novel approach to the tetracyclic frameworks of anislactone-type sesquiterpenoids

Abstract

Herein, we present a novel approach to construct the A-B-C-D ring system of anislactone-type sesquiterpenoids. This innovative strategy involves a H₂O₂-mediated oxidative ring contraction reaction to form a 5/5 fused skeleton, while simultaneously generating contiguous quaternary carbon centers (CQCCs). Additionally, γ-lactones (A- and D-rings) are assembled through Pummerer reaction initiated cyclization and sequential Mukaiyama hydration/translactonization, respectively. Despite our efforts to introduce a hydroxyl group at C7 via C–H oxidation, these endeavors ultimately proved unsuccessful.