1: PBr3 / diethyl ether / 1.5 h / 0 °C 2: 75 percent / 1.) hexamethylphosphoric triamide, BuLi / tetrahydrofuran; hexane / -70 - 0 °C 3: 1.) CuCl2, LiAlH4, MeOLi; 2.) ceric ammonium nitrate / 1.) THF, 1 h, reflux; 2.) CH2Cl2, CH3CN, H2O, 0 deg C View Scheme

1: 445 mg / SO2Cl2 / pyridine; CH2Cl2 / 1 h / -20 °C 2: dimethylformamide / 1.) 0 deg C, 1 h; 2.) r.t., 30 min 3: 30percent H2O2 / acetic acid / Ambient temperature 4: trimethyl phosphite / methanol / Ambient temperature View Scheme

1: 30percent H2O2 / acetic acid / Ambient temperature 2: trimethyl phosphite / methanol / Ambient temperature View Scheme

1: dimethylformamide / 1.) 0 deg C, 1 h; 2.) r.t., 30 min 2: 30percent H2O2 / acetic acid / Ambient temperature 3: trimethyl phosphite / methanol / Ambient temperature View Scheme