[C:1]([O:5][C:6]([NH:8][C@H:9]([CH3:12])[CH2:10][OH:11])=[O:7])([CH3:4])([CH3:3])[CH3:2].[H-].[Na+].[CH2:15](Br)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1.O>C1COCC1.[I-].C([N+](CCCC)(CCCC)CCCC)CCC>[CH2:15]([O:11][CH2:10][C@H:9]([NH:8][C:6]([O:5][C:1]([CH3:4])([CH3:3])[CH3:2])=[O:7])[CH3:12])[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1Dissolve (R)-(+)-2-(tert-butoxycarbonylamino)-1-propanol (875 mg, 5 mmol) in anhydrous THF (50 mL). Add sodium hydride (60% in mineral oil, 210 mg, 5.2 mmol) and stir at 0° C. for 30 min. Add benzyl bromide (620 μL, 5.2 mmol) followed by tetrabutylammonium iodide (20 mg, 0.05 mmol) and stir for 3 h at ambient temperature. Pour the mixture into water (200 mL), extract with DCM (3×50 mL), wash with brine, dry over MgSO4, filter and concentrate. Purify by chromatography on silica gel eluting with hexane/EtOAc (19:1) to give the desired intermediate as a colorless oil (800 mg, 60%).
読み込み中…
