Visible-light-induced consecutive C–C bond fragmentation and formation for the synthesis of elusive unsymmetric 1,8-dicarbonyl compounds

Synthesis of the valuable unsymmetric 1,8-dicarbonyl compounds remains underexplored currently. Herein, we disclose a new strategy for the synthesis of 1,8-diketones through the coupling of cyclopropanols and cyanohydrins under visible-light irradiation. The protocol features a cascade of intriguing ring opening of cyclopropanols and remote cyano migration. The unfavorable addition of an alkyl radical to an electron-rich alkene is facilitated by the intramolecular cyanohydrin interception. A variety of multiply functionalized 1,8-diketones are furnished in useful yields. The products could be further transformed into other valuable compounds, manifesting the utility of this method.