1: 75 percent / pyridinium chlorochromate, molecular sieve 3 A / CH2Cl2 / 1.5 h / Ambient temperature 2: 59 percent / CH2Cl2 / 16 h / Ambient temperature 3: 61 percent / hydrogen / palladium black / methanol / 48 h 4: H2 / palladium black / acetic acid / 72 h / Ambient temperature 5: 74 percent / trifluoroacetic acid / D2O / 50 h / Ambient temperature View Scheme

With  3 A molecular sieve; pyridinium chlorochromate in  dichloromethane 1.5 h;  Ambient temperature;