1: 59 percent / CH2Cl2 / 16 h / Ambient temperature 2: 61 percent / hydrogen / palladium black / methanol / 48 h 3: H2 / palladium black / acetic acid / 72 h / Ambient temperature 4: 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;