[CH2:1]([O:8][C:9]([NH:11][C@H:12]([C:18](=[O:20])[NH2:19])[CH2:13][CH2:14][C:15]([OH:17])=[O:16])=[O:10])[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[C:21]1(C)C=CC(S(O)(=O)=O)=C[CH:22]=1>C(O)C>[CH2:21]([O:16][C:15](=[O:17])[CH2:14][CH2:13][C@@H:12]([C:18](=[O:20])[NH2:19])[NH:11][C:9]([O:8][CH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1)=[O:10])[CH3:22]A suspension of 15.98 g of N-Benyloxycarbonyl-L-isoglutamine in 500 mL of absolute ethanol containing 0.54 g of p-toluenesulfonic acid is refluxed for 12 hours until TLC indicated that the reaction is complete. The solution is concentrated to a small volume and addition f ether gave a solid. The solid is filtered and recrystallized to give 16.0 of N-Benyloxycarbonyl-L-isoglutamine ethyl ester, 16.
불러오는 중…