in pyridine T=-10°C; 6 h;

1: 1.) C6H5Li / 1.) toluene, ether; 2.) toluene, THF, ether, -30 deg C, 20 min 2: 1.) pyridine, (CF3CO)2O, 2.) NaN3 / 1.) CH2Cl2, -15 deg C, 15 min; 2.) CH2Cl2, DMF, room temperature, 5 h 3: 75 percent / p-TsOH / methanol; CH2Cl2 / 12 h / Ambient temperature 4: 75 percent / pyridine / 6 h / -10 °C View Scheme

1: 68 percent / p-TsOH / methanol; CH2Cl2 / 12 h / Ambient temperature 2: 75 percent / pyridine / 6 h / -10 °C View Scheme

1: 1.) pyridine, (CF3CO)2O, 2.) NaN3 / 1.) CH2Cl2, -15 deg C, 15 min; 2.) CH2Cl2, DMF, room temperature, 5 h 2: 68 percent / p-TsOH / methanol; CH2Cl2 / 12 h / Ambient temperature 3: 75 percent / pyridine / 6 h / -10 °C View Scheme

1: 1.) pyridine, (CF3CO)2O, 2.) NaN3 / 1.) CH2Cl2, -15 deg C, 15 min; 2.) CH2Cl2, DMF, room temperature, 5 h 2: 75 percent / p-TsOH / methanol; CH2Cl2 / 12 h / Ambient temperature 3: 75 percent / pyridine / 6 h / -10 °C View Scheme

1: 75 percent / p-TsOH / methanol; CH2Cl2 / 12 h / Ambient temperature 2: 75 percent / pyridine / 6 h / -10 °C View Scheme