Visible-Light-Promoted Intramolecular C-O Bond Formation via CH Functionalization: A Straightforward Synthetic Route to Biorelevant Dihydrofuro[3,2-]chromenone Derivatives.

A photochemical method for the synthesis of functionalized dihydrofuro[3,2-]chromenones via intramolecular C-H -dehydrogenative oxygenation within a warfarin framework has been unearthed. Advantages of this protocol include abundant sunlight or low-energy visible light as the energy source, mild reaction conditions, and avoidance of metal catalysts.