Visible-Light-Enabled Catalytic Intramolecular Double Oxidation of Olefins to <i>ortho</i>-Hydroxylactones

We have effectively utilized cost-effective 2-bromoanthraquinone as a photocatalyst to develop an efficient and environmentally friendly method for producing <i>o</i>-hydroxy lactones under mild visible light irradiation. Importantly, this protocol only relies on oxygen as an oxidant, completely eliminating the need for additional chemical reagents and showcasing a sustainable approach to chemical transformation. Operating at room temperature, we utilized a mixed solvent system of DMF and CHCl₃, which greatly facilitated the selective conversion of various 2-vinylbenzoic acids and carboxylic acids to functional <i>o</i>-hydroxyl lactones. The process also exhibited excellent diastereoselectivity. Moreover, this versatile strategy is compatible with a wide range of biologically active and complex molecules, offering new opportunities for late-stage structural modifications of these compounds.