[C:1]([O:5][C:6]([NH:8][CH2:9][CH:10]([C:14]1[CH:19]=[CH:18][C:17]([CH2:20][O:21][Si:22]([CH:29]([CH3:31])[CH3:30])([CH:26]([CH3:28])[CH3:27])[CH:23]([CH3:25])[CH3:24])=[CH:16][CH:15]=1)[C:11]([OH:13])=[O:12])=[O:7])([CH3:4])([CH3:3])[CH3:2].[CH3:32]I.[H-].[Na+]>C1COCC1.CCOC(C)=O>[C:1]([O:5][C:6]([N:8]([CH3:32])[CH2:9][CH:10]([C:14]1[CH:15]=[CH:16][C:17]([CH2:20][O:21][Si:22]([CH:23]([CH3:24])[CH3:25])([CH:26]([CH3:28])[CH3:27])[CH:29]([CH3:31])[CH3:30])=[CH:18][CH:19]=1)[C:11]([OH:13])=[O:12])=[O:7])([CH3:4])([CH3:2])[CH3:3]To 3-(tert-butoxycarbonylamino)-2-(4-((triisopropylsilyloxy)methyl)phenyl)propanoic acid (E203) in THF under N2 and cooled to 0° C. was added CH3I followed by NaH and the solution was warmed and allowed to stir for 18 h. The mixture was taken up in EtOAc and extracted with NH4Cl(sat), dried (MgSO4), filtered, and evaporated. Column chromatography (SiO2, 0-10% MeOH/CH2Cl2 gradient) gave pure 3-(tert-butoxycarbonyl(methyl)amino)-2-(4-((triisopropylsilyloxy)methyl)phenyl)propanoic acid (E204).
Wird geladen…