A unique peroxide formation based on the Mn(III)-catalyzed aerobic oxidation

The autoxidation of a mixture of 1,1-diarylsubstituted alkenes 4 and 4-hydroxy-1H-quinolin-2-ones 5 in the presence of a catalytic amount of manganese(III) acetate dihydrate in air gave 3,3-bis(2-hydroperoxyethyl)-1H-quinoline-2,4-diones 6 in 31–91% yields together with [4.4.3]propellane-type cyclic peroxides 7 (10–34%). A similar aerobic oxidation of 3-substituted quinolinones 8 yielded cyclic peroxide derivatives 9 and/or 3-hydroperoxyethylated quinolinediones 10 depending on the substituent. The structures of the bis(hydroperoxide) 6 (R1=Me, Ar=4-ClC6H4) and the [4.4.3]propellane 7 (R1=Me, Ar=Ph) have been corroborated by X-ray crystallography.