Chemoselective and Diastereoconvergent Cu(II)-Catalyzed Aerobic Endoperoxidation of Polycarbonyls

The diastereoconvergent synthesis of spirocyclic endoperoxides using a Meldrum’s acid scaffold has been accomplished by employing readily available feedstock chemicals. Site selective C–H oxidation of the bis­(β-dicarbonyl) substrates was performed using elemental oxygen as the stoichiometric oxidant and a commercial Cu­(II) catalyst. Sequential hydrogenolysis and ionic reduction of these endoperoxides provided fully substituted tetrahydrofurans in high yields and diastereoselectivity.