Formal total synthesis of (±)-liphagal

Abstract

A formal total synthesis of (±)-liphagal is reported. The key features of the synthetic route include a novel copper/1,2,4-benzenetriol-promoted hydroxybenzofuran formation from an alkynylquinone via an organic redox process, a silver(I)-catalyzed cationic seven-membered ring construction, and a stereoconvergent synthesis of the desired diastereomer with the natural relative configuration through unsaturation followed by stereoselective hydrogenation.