[CH2:1]([O:8][C@H:9]1[C@H:13]([O:14][CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=2)[CH2:12][NH:11][C@@H:10]1[CH2:22][O:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[CH2:31]=O>C(O)=O>[CH2:1]([O:8][C@H:9]1[C@H:13]([O:14][CH2:15][C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=2)[CH2:12][N:11]([CH3:31])[C@@H:10]1[CH2:22][O:23][CH2:24][C:25]1[CH:30]=[CH:29][CH:28]=[CH:27][CH:26]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1A mixture of (2R,3R,4R)-3,4-dibenzyloxy-2-benzyloxymethylpyrrolidine (Compound 1) (0.5 g, 1.24 mmol), formic acid (10 ml) and 37% formaldehyde (7.5 ml) was heated for 3 hours at reflux temperature and evaporated in vacuo. The residue was dissolved in a mixture of ethyl acetate (25 ml) and 1N sodium hydroxide (25 ml). The organic phase was isolated, washed once with water, dried over magnesium sulphate and evaporated in vacuo to give (2R,3R,4R)-3,4-dibenzyloxy-2-benzyloxymethyl-1-methylpyrrolidine (0.49 g, yield: 95%) as a golden oil.
Wird geladen…