[CH3:1][O:2][C:3](=[O:31])[CH:4]=[CH:5][C:6]1[CH:11]=[CH:10][C:9]([O:12][C:13]2[CH:18]=[CH:17][C:16]([CH:19]([NH:23][C:24]([O:26][C:27]([CH3:30])([CH3:29])[CH3:28])=[O:25])[C:20]([OH:22])=[O:21])=[CH:15][CH:14]=2)=[CH:8][CH:7]=1.[H][H]>[Ni].CO>[CH3:1][O:2][C:3](=[O:31])[CH2:4][CH2:5][C:6]1[CH:7]=[CH:8][C:9]([O:12][C:13]2[CH:18]=[CH:17][C:16]([CH:19]([NH:23][C:24]([O:26][C:27]([CH3:29])([CH3:28])[CH3:30])=[O:25])[C:20]([OH:22])=[O:21])=[CH:15][CH:14]=2)=[CH:10][CH:11]=1Raney nickel 2800 (21.9 g) was added to a degassed solution of the unsaturated ester 30 (20.0 g) in MeOH (100 mL) and the resulting suspension was treated with hydrogen at atmospheric pressure for 18 h. The suspension was filtered over a Celite® bed and concentrated. Completion of hydrogenation was determined by NMR. Flash chromatography (20-50% ethyl acetate in hexane containing 1% acetic acid) of the resulting residue gave the desired saturated ester 31 (15.1 g, 75%). 1H NMR (400 MHz, DMSO-d6): 12.8 (br, 1H), 7.37 (d, J=8.8 Hz, 2H), 7.24 (d, J=8.4 Hz, 2H), 6.93 (d, J=8.4 Hz, 4H), 3.59 (s, 3H), 2.84 (t, J=7.6 Hz, 2H), 2.63 (t, J=7.6 Hz, 2H) 1.39 (s, 9H).
Wird geladen…