Synthesis of Asymmetric Peroxides: Transition Metal (Cu, Fe, Mn, Co) Catalyzed Peroxidation of β-Dicarbonyl Compounds with tert-Butyl Hydroperoxide

The transition metal (Cu, Fe, Mn, Co) catalyzed peroxidation of β-dicarbonyl compounds at the α position by tert-butyl hydroperoxide was discovered. A selective, experimentally convenient, and gram-scale method was developed for the synthesis of α-peroxidated derivatives of β-diketones, β-keto esters, and diethyl malonate. Virtually stoichiometric (2−3/1) molar ratios of tert-butyl hydroperoxide and a dicarbonyl compound were used in the reactions with β-diketones and β-keto esters. The target compounds were synthesized in the highest yields from β-keto esters (45−90%) and in somewhat lower yields from β-diketones (46−75%) and malonates (37−67%).