[OH:1][C@@H:2]1[CH2:5][C@H:4]([NH:6][C:7](=[O:13])[O:8][C:9]([CH3:12])([CH3:11])[CH3:10])[CH2:3]1.[H-].[Na+].I[CH3:17]>C1COCC1>[C:9]([O:8][C:7](=[O:13])[NH:6][C@H:4]1[CH2:3][C@@H:2]([O:1][CH3:17])[CH2:5]1)([CH3:10])([CH3:12])[CH3:11]tert-Butyl (cis-3-hydroxycyclobutyl)carbamate (0.8 g, 4.3 mmol) was dissolved in dry THF (25 mL) under a nitrogen atmosphere, and the solution cooled to 0° C. To this clear solution, sodium hydride (60% dispersion in oil, 0.17 g, 4.3 mmol) was added portion wise (evolution of H2 observed). The mixture was stirred at RT for 30 min. then iodomethane (0.40 mL, 1.5 mmol) added dropwise and the resulting yellow suspension stirred at rt for 16 h. The reaction mixture was quenched with saturated aqueous solution of NH4Cl (20 mL) and partitioned between saturated aqueous solution of NaHCO3 (40 mL) and DCM (60 mL). The combined organic fractions were washed with brine (20 mL), dried (MgSO4) and concentrated in vacuo. The resulting residue was purified by column chromatography (gradient 0-70% EtOAc in cyclohexane) to afford the title compound as a white solid (0.58 g, 66%). 1H NMR (CDCl3, 300 MHz): δ 4.66 (1H, br, NH), 3.71-3.62 (1H, m), 3.61-3.50 (1H, m), 2.71 (3H, s), 2.76-1.62 (2H, m), 1.78-1.62 (2H, m), 1.41 (9H, s).
Wird geladen…
