1: 81 percent / potassium superoxide / 18-crown-6 / dimethylsulfoxide; dimethylformamide; 1,2-dimethoxy-ethane / 6 h / Ambient temperature 2: 100 percent / triethylamine / benzene / 2 h / Ambient temperature 3: acetonitrile / 36 h / 65 - 70 °C View Scheme

potassium superoxide; 18-crown-6 ether in ethylene glycol dimethyl ether; dimethyl sulfoxide; N,N-dimethyl-formamide 6 h; Ambient temperature;

Multi-step reaction with 2 steps 1: 81 percent / potassium superoxide / 18-crown-6 / dimethylsulfoxide; dimethylformamide; 1,2-dimethoxy-ethane / 6 h / Ambient temperature2: 100 percent / triethylamine / benzene / 2 h / Ambient temperature