1: 94 percent / HCl gas / 10 h / Ambient temperature 2: p-TsOH*H2O / acetone / 2 h / Ambient temperature 3: PDC, Ac2O / CH2Cl2 / 4 h / Heating 4: NaBH4 / methanol / 3 h / -20 °C 5: CF3CO2H / Heating 6: HCl / 2 h / Ambient temperature 7: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 8: AcOH, H2SO4 / 0 °C 9: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 10: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 11: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

1: p-TsOH*H2O / acetone / 2 h / Ambient temperature 2: PDC, Ac2O / CH2Cl2 / 4 h / Heating 3: NaBH4 / methanol / 3 h / -20 °C 4: CF3CO2H / Heating 5: HCl / 2 h / Ambient temperature 6: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 7: AcOH, H2SO4 / 0 °C 8: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 9: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 10: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

1: PDC, Ac2O / CH2Cl2 / 4 h / Heating 2: NaBH4 / methanol / 3 h / -20 °C 3: CF3CO2H / Heating 4: HCl / 2 h / Ambient temperature 5: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 6: AcOH, H2SO4 / 0 °C 7: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 8: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 9: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

1: AcOH, H2SO4 / 0 °C 2: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 3: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 4: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

1: CF3CO2H / Heating 2: HCl / 2 h / Ambient temperature 3: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 4: AcOH, H2SO4 / 0 °C 5: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 6: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 7: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

1: HCl / 2 h / Ambient temperature 2: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 3: AcOH, H2SO4 / 0 °C 4: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 5: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 6: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme

1: pyridine / 1.) room temperature, 8 h, 2.) 45 deg C, 1.5 h 2: AcOH, H2SO4 / 0 °C 3: 1.) HCl gas, AcCl, 2.) H2O / 1.) CH2Cl2, 0 deg C, 12 h, 2.) MeCN, 0 deg C, 30 min 4: 1.) SO2Cl2 / 1.) CH2Cl2, DMF, room temperature, 3 h, 2.) room temperature, 20 h 5: 1.) Et3N*3HF, 2.) Et3N / 1.) EtOAc, 80 deg C, 3 h, 2.) 80 deg C, 1 h View Scheme