1: thionyl chloride / dimethylformamide / 12 h / Ambient temperature 2: 75 percent / 36percent w/w hydrogen peroxide / acetic acid / 6 h / steam-bath 3: sodium borohydride / tetrahydrofuran; methanol / 3 h 4: 2. PbO2 / 1. THF, r.t., 3h; 2. benzene View Scheme

1: thionyl chloride / dimethylformamide / 12 h / Ambient temperature 2: 75 percent / 36percent w/w hydrogen peroxide / acetic acid / 6 h / steam-bath 3: 2. PbO2 / 1. THF, r.t., 3h; 2. benzene View Scheme