Visible-Light-Enabled\nCatalytic Intramolecular Double\nOxidation of Olefins to <i>ortho</i>-Hydroxylactones

We have effectively utilized cost-effective 2-bromoanthraquinone\nas a photocatalyst to develop an efficient and environmentally friendly\nmethod for producing <i>o</i>-hydroxy lactones under mild\nvisible light irradiation. Importantly, this protocol only relies\non oxygen as an oxidant, completely eliminating the need for additional\nchemical reagents and showcasing a sustainable approach to chemical\ntransformation. Operating at room temperature, we utilized a mixed\nsolvent system of DMF and CHCl<sub>3</sub>, which greatly facilitated\nthe selective conversion of various 2-vinylbenzoic acids and carboxylic\nacids to functional <i>o</i>-hydroxyl lactones. The process\nalso exhibited excellent diastereoselectivity. Moreover, this versatile\nstrategy is compatible with a wide range of biologically active and\ncomplex molecules, offering new opportunities for late-stage structural\nmodifications of these compounds.