trifluoroacetic acid 6 h; Ambient temperature;

1: pyridine / CH2Cl2 / 0.5 h 2: NaN3 / dimethylformamide / 0.5 h / Ambient temperature 3: 93 percent / sodium borohydride / ethanol / 18 h / Ambient temperature 4: 94 percent / 4-dimethylaminopyridine, pyridine / 1) 0 deg C, 4 h, 2) 18 h, room temperature 5: 1) H2, 2) NaOAc / 1) 10percent palladium black / 1) EtOH, 2 h, room temperature, 2) 50 deg C, 12 h 6: 90 percent / 50percent aq. CF3CO2H / 6 h / Ambient temperature View Scheme

1: 93 percent / sodium borohydride / ethanol / 18 h / Ambient temperature 2: 94 percent / 4-dimethylaminopyridine, pyridine / 1) 0 deg C, 4 h, 2) 18 h, room temperature 3: 1) H2, 2) NaOAc / 1) 10percent palladium black / 1) EtOH, 2 h, room temperature, 2) 50 deg C, 12 h 4: 90 percent / 50percent aq. CF3CO2H / 6 h / Ambient temperature View Scheme

1: 55 percent / imidazole / dimethylformamide / 1) 0 deg C --> room temperature, 3 h, 2) 22 h 2: 68 percent / DL-camphorsulphonic acid / acetone / 22 h / 50 °C / Heating 3: 86 percent / tetrabutylammonium fluoride / tetrahydrofuran / 1.5 h 4: pyridine / CH2Cl2 / 0.5 h 5: NaN3 / dimethylformamide / 0.5 h / Ambient temperature 6: 93 percent / sodium borohydride / ethanol / 18 h / Ambient temperature 7: 94 percent / 4-dimethylaminopyridine, pyridine / 1) 0 deg C, 4 h, 2) 18 h, room temperature 8: 1) H2, 2) NaOAc / 1) 10percent palladium black / 1) EtOH, 2 h, room temperature, 2) 50 deg C, 12 h 9: 90 percent / 50percent aq. CF3CO2H / 6 h / Ambient temperature View Scheme