1: sodium borohydride / ethanol / 1 h / 0 °C 2: pyridine / CH2Cl2 / 8 h / -20 °C 3: sodium azide / dimethylformamide / 16 h / Ambient temperature 4: 97 percent / tetrabutylammonium fluoride / tetrahydrofuran / 4 h / Ambient temperature 5: 100 percent / hydrogen / palladium black / methanol / 1 h / Ambient temperature 6: aq. sodium bicarbonate / diethyl ether / 1.5 h / 0 °C 7: 75 percent / pyridinium chlorochromate, molecular sieve 3 A / CH2Cl2 / 1.5 h / Ambient temperature 8: 59 percent / CH2Cl2 / 16 h / Ambient temperature 9: 61 percent / hydrogen / palladium black / methanol / 48 h 10: H2 / palladium black / acetic acid / 72 h / Ambient temperature 11: 74 percent / trifluoroacetic acid / D2O / 50 h / Ambient temperature View Scheme