Total Syntheses of the Reported Structures of Curcusones I and J through Tandem Gold Catalysis

Abstract

AbstractTotal syntheses of the reported structures of the rhamnofolane diterpene natural products curcusones I and J in racemic form were achieved. The synthetic strategy features a novel tandem gold‐catalyzed furan formation and furan–allene [4+3] cycloaddition to build the 5,7‐fused ring system with an oxa‐bridge in one step, and a stereoselective exo‐Diels–Alder reaction to form the 6‐membered ring. The newly developed tandem gold catalysis is quite general and can be scaled up. Our syntheses suggest that structural revisions of curcusones I and J are needed.