A C-H Functionalization Strategy Enables an Enantioselective Formal Synthesis of (-)-Aflatoxin B.

An enantioselective formal synthesis of (-)-aflatoxin B from 4-methoxyphenylacetic acid has been achieved by an approach that produces a key carbon-carbon bond, a benzylic stereocenter, and two arene carbon-oxygen bonds in the course of three site-selective C-H functionalizations. The carbonyl-directed acetoxylation of two arene C-H bonds described herein is unprecedented in natural product synthesis and occurs under mild conditions that preserve the configuration of a sensitive benzylic stereocenter.