Total syntheses of Ganoderma -derived meroterpenoids, (-)-oregonensin A, (-)-chizhine E, (-)-applanatumol U, and (-)- ent -fornicin A.

In this study, we report the total syntheses of Ganoderma -derived meroterpenoids, (-)-oregonensin A, (-)-chizhine E, (-)-applanatumol U, and (-)- ent -fornicin A. The 3-alkyl-5-aryl-γ-butenolide skeleton, a common motif of these meroterpenoids, was constructed through the enantioselective reductive lactonization of the γ-keto ester, alkylation, and sulfoxide-β- syn -elimination. This flexible approach enabled enantioselective access to these meroterpenoids with the longest linear sequence of 6-8 steps, and in 21-36% overall yield, respectively.