Asymmetric Total Synthesis and Structure Revision of (+)-Mangicol D

Isolated from the marine fungus Fusarium heterosporum, mangicols represent a new class of sesterterpenoids featuring unprecedented spirotetracyclic cores and notable bioactivities. Herein, we report the first asymmetric synthesis of a mangicol sesterterpene exploiting a domino carbopalladation-carbonylation, Conia-ene cyclization, and SmI2-mediated reductive cyclization to establish the spiro-fused tetracyclic framework in a concise manner. Our findings suggest a stereochemical revision of the polyol side chain of the initially isolated mangicols.