[H-].[Na+].[C:3]([O:7][C:8](=[O:26])[C@@H:9]([CH2:22][CH:23]([CH3:25])[CH3:24])[NH:10][S:11]([C:14]1[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=1)(=[O:13])=[O:12])([CH3:6])([CH3:5])[CH3:4].[CH2:27](Br)[C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1>CN(C)C=O>[CH3:21][O:20][C:17]1[CH:16]=[CH:15][C:14]([S:11]([N:10]([CH2:27][C:28]2[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=2)[C@H:9]([CH2:22][CH:23]([CH3:24])[CH3:25])[C:8]([O:7][C:3]([CH3:6])([CH3:5])[CH3:4])=[O:26])(=[O:13])=[O:12])=[CH:19][CH:18]=1To a suspension of sodium hydride (0.68 g, 14.1 mmol) in dimethylformamide (60.0 mL), is added N-[4-methoxybenzenesulfonyl]-(D)-leucine t-butyl ester (5.02 g, 14.06 mmol) in dimethylformamide (10.0 mL). After stirring at room temperature for 20 minutes, benzyl bromide (1.67 mL, 14.06 mmol) is added, and the reaction is stirred overnight at room temperature. The reaction is then partitioned between ethyl acetate and acidic water (pH=5), the organic layer is dried (Na2SO4), and the solvent is evaporated. The product is purified by silica gel chromatography (10% ethyl acetate/hexane) to give t-butyl 2(R)-[[4-methoxybenzenesulfonyl](benzyl)amino]-4-methylpentanoate.
불러오는 중…