Total Synthesis of (±)-Cochlearol A.

Total synthesis of (±)-cochlearol A was accomplished, which features a cis 6/6 B/D ring synthesis. A TMSOTf-promoted lactonization of tert-butoxy ketoester produced the desired lactone with quaternary carbon. The cis configuration of the B/E ring is essential for regioselective B/D ring formation. Finally, simple deprotections and transformations gave cochlearol A in 16 steps from known ethyl 4-tert-butoxyacetoacetate.

Enantioselective total synthesis of (+)-Lingzhiol via tandem semipinacol rearrangement/Friedel-Crafts type cyclization.

Enantioselective total synthesis of (+)-Lingzhiol has been achieved. It is the first example of in tandem semipinacol rearrangement reactions, the migrated aryl group further reacting with the carbonyl oxonium electrophile to furnish a polycyclic skeleton. Our synthesis involves 13 steps and proceeds in 6% overall yield.

Catalytic Asymmetric Formal Total Synthesis of (-)-Triptophenolide and (+)-Triptolide.

Catalytic asymmetric formal synthesis of (-)-Triptophenolide and (+)-Triptolide have been achieved. Key reaction involves Palladium catalyzed asymmetric conjugate addition of aryl boronic acid to 3-methyl cyclohexe-1-none to form quaternary carbon. Claisen rearrangement and subsequent aldol reaction furnished trans-decaline key intermediate, which assured a formal total synthesis of (-)-Triptophenolide and (+)-Triptolide.

Concise synthesis of (±)-Lingzhiol via epoxy-arene cyclization.

Concise synthesis of (±)-Lingzhiol has been achieved. The key reaction involves one-step construction of a 5/5/6/6 tetra-ring backbone of Lingzhiol via epoxy-arene cyclization.