Synthesis of Rhodocorane L Using Gold-Catalyzed Dearomative Spirocyclization.

Reported herein is the first total synthesis of the acorane-type terpenoid rhodocorane L, isolated from the fungus . This unique tricyclic scaffold containing a spiro[4.5] bicycle has antifungal activity. Key steps include diastereoselective cuprate addition, gold-catalyzed dearomative spirocyclization, and intramolecular aldol. This is the first time that a catalyst-controlled asymmetric dearomative spirocyclization has been utilized in a total synthesis. Rhodocorane L was synthesized in 17 steps, as the longest linear sequence.