1: 44 percent / PCC / CH2Cl2 / 3.5 h / Ambient temperature 2: 96 percent / ethanethiol, BF3*Et2O / CH2Cl2 / 0.5 h / Ambient temperature View Scheme

Multi-step reaction with 8 steps 1: CrO3 / pyridine / 12 h / Ambient temperature2: 92 percent / diethyl ether / 5 h / 0 °C3: 82 percent / POCl3 / pyridine / 8 h / Ambient temperature4: 92 percent / BF3*Et2O / CH2Cl2 / 1 h / Ambient temperature5: 81 percent / iPr2NEt / CH2Cl2 / 7 h / Ambient temperature6: 59 percent / Na2CO3, MeI / H2O; acetonitrile / 3 h / Heating7: 1.) HMPA, 15percent w/w n-BuLi / 1.) THF, hexane, -78 deg C, 15 min; 2.) THF, -78 deg C, 10 min; 0 deg C, 30 min; rt, 6 h