A Concise Synthesis of Pleurotin Enabled by a Nontraditional C-H Epimerization.

An 8-step synthesis of a known pentacyclic intermediate toward the natural product pleurotin ( 1 ) is described. Pleurotin and related benzoquinone natural products are of great interest for their powerful anticancer and antibiotic activities. The route features a regio- and diastereoselective intermolecular photoenolization/Diels-Alder cycloaddition and an alkoxy-radical-induced hydrogen atom transfer-mediated C-H epimerization to construct pleurotin's carbon framework with appropriate relative stereochemical relationships. The synthesis concludes with a ring-forming benzylic C-H oxidation to deliver oxepane 19 .