diethylamino-sulfur trifluoride in dichloromethane T=0°C; 1 h; Inert atmosphere; regioselective reaction;

acetic acid; zinc T=118°C; Clemmensen reduction; 0.25 h;

chromium(VI) oxide

1: CrO3 / pyridine / 12 h / Ambient temperature 2: 92 percent / diethyl ether / 5 h / 0 °C 3: 82 percent / POCl3 / pyridine / 8 h / Ambient temperature 4: 92 percent / BF3*Et2O / CH2Cl2 / 1 h / Ambient temperature 5: 81 percent / iPr2NEt / CH2Cl2 / 7 h / Ambient temperature 6: 59 percent / Na2CO3, MeI / H2O; acetonitrile / 3 h / Heating 7: 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 8: 2.) ethanethiol, BF3*Et2O / 1.) Methylene Blue / 1.) toluene, 220 deg C, 100 h; 2.) CH2Cl2, rt, 1 h 9: 52 percent / CrO3 / pyridine / 10 h / Ambient temperature View Scheme

diethylamino-sulfur trifluoride in dichloromethane T=0°C; 1 h; Inert atmosphere; regioselective reaction;

1: 82 percent / POCl3 / pyridine / 8 h / Ambient temperature 2: 92 percent / BF3*Et2O / CH2Cl2 / 1 h / Ambient temperature 3: 81 percent / iPr2NEt / CH2Cl2 / 7 h / Ambient temperature 4: 59 percent / Na2CO3, MeI / H2O; acetonitrile / 3 h / Heating 5: 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 6: 2.) ethanethiol, BF3*Et2O / 1.) Methylene Blue / 1.) toluene, 220 deg C, 100 h; 2.) CH2Cl2, rt, 1 h 7: 52 percent / CrO3 / pyridine / 10 h / Ambient temperature View Scheme

1: 81 percent / iPr2NEt / CH2Cl2 / 7 h / Ambient temperature 2: 59 percent / Na2CO3, MeI / H2O; acetonitrile / 3 h / Heating 3: 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 4: 2.) ethanethiol, BF3*Et2O / 1.) Methylene Blue / 1.) toluene, 220 deg C, 100 h; 2.) CH2Cl2, rt, 1 h 5: 52 percent / CrO3 / pyridine / 10 h / Ambient temperature View Scheme

1: 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 2: 2.) ethanethiol, BF3*Et2O / 1.) Methylene Blue / 1.) toluene, 220 deg C, 100 h; 2.) CH2Cl2, rt, 1 h 3: 52 percent / CrO3 / pyridine / 10 h / Ambient temperature View Scheme

1: 92 percent / BF3*Et2O / CH2Cl2 / 1 h / Ambient temperature 2: 81 percent / iPr2NEt / CH2Cl2 / 7 h / Ambient temperature 3: 59 percent / Na2CO3, MeI / H2O; acetonitrile / 3 h / Heating 4: 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 5: 2.) ethanethiol, BF3*Et2O / 1.) Methylene Blue / 1.) toluene, 220 deg C, 100 h; 2.) CH2Cl2, rt, 1 h 6: 52 percent / CrO3 / pyridine / 10 h / Ambient temperature View Scheme

1: 59 percent / Na2CO3, MeI / H2O; acetonitrile / 3 h / Heating 2: 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 3: 2.) ethanethiol, BF3*Et2O / 1.) Methylene Blue / 1.) toluene, 220 deg C, 100 h; 2.) CH2Cl2, rt, 1 h 4: 52 percent / CrO3 / pyridine / 10 h / Ambient temperature View Scheme