Enantioselective Total Synthesis of (+)‐Propolisbenzofuran B^†

Abstract

Comprehensive SummaryThe first catalytic asymmetric total synthesis of (+)‐propolisbenzofuran B, enabled by a highly enantioselective rhodium‐catalyzed hydrogenation of a tetrasubstituted olefin, was described. Other noteworthy aspects include the construction of the central hydrodibenzo[b,d]furan core through a sequence of Zn(II)‐mediated regioselective benzofuran formation and Dieckmann condensation, as well as C‐H oxidations, involving a visible light‐induced Fe(III)‐catalyzed benzylic C(sp3)‐H oxidation. Additionally, the absolute configuration was confirmed by X‐ray analysis of a carbonate intermediate.