An enantioselective total synthesis of (+)-lepadin F is described. The synthetic sequence features an intermolecular aza-[3 + 3] annulation, homologation of a vinylogous amide via Eschenmoser's episulfide contraction, and a highly stereoselective hydrogenation essential for achieving the 1,3-anti relative stereochemistry at C2 and C8a.
Stereodivergent Approach to Both C2,8a-syn and C2,8a-anti Relative Stereochemical Manifolds in the Lepadin Family via a TiCl4-Promoted Aza-[3+3] Annulation