Total Synthesis of Applanatumol B.

The first total synthesis of the tricyclic meroterpenoid applanatumol B, isolated from Ganoderma applanatum, was accomplished in 14 steps from 2,5-dimethoxybenzaldehyde and 4-pentyn-1-ol. The synthetic features include an intramolecular Morita-Baylis-Hillman reaction, a stereoselective Michael addition, and efficient construction of the tricyclic skeleton under acidic conditions involving epimerization at the α-position of the ketone.