1: 1) DMSO, (COCl)2, 2) Et3N / 1) CH2Cl2, -60 to -50 deg C, 15 min, 2a) CH2Cl2, -60 deg C, 10 min, 2b) to RT, 1 h 2: 1) n-BuLi / 1) THF, hexane, -10 deg C, 2 min, 2) -10 to +20 deg C, 2 h 3: PHSSPh / Irradiation 4: 89 percent / BF3*Et2O, (CH2SH)2 / CH2Cl2 / 0.5 h / 20 °C View Scheme

1: 1) DMSO, (COCl)2, 2) Et3N / 1) CH2Cl2, -60 to -50 deg C, 15 min, 2a) CH2Cl2, -60 deg C, 10 min, 2b) to RT, 1 h 2: 1) n-BuLi / 1) THF, hexane, -10 deg C, 2 min, 2) -10 to +20 deg C, 2 h 3: PHSSPh / Irradiation 4: 89 percent / BF3*Et2O, (CH2SH)2 / CH2Cl2 / 0.5 h / 20 °C View Scheme