Iron‐Catalyzed Synthesis of the Hexahydrocyclopenta[ c ]furan Core and Concise Total Synthesis of Polyflavanostilbene B

The first synthesis of polyflavanostilbene B ( 1 ), which has seven contiguous stereocenters including two quaternary carbon centers, from abundant polymeric (−)‐epicatechin gallate on a gram scale in three steps without the use of protecting groups is reported. The key transformations of this strategy include a regioselective and stereoselective substitution of resveratrol to give the 4‐derivative of (−)‐epicatechin 3‐gallate and an iron‐catalyzed cyclization reaction. The possible radical cyclization mechanism in the formation of the hexahydrocyclopenta[c]furan core is also discussed.