反应详情

To a solution of (3aR,4R,4aR,8aR,9aS)-4-hydroxy-3-(methoxy(phenyl)methyl)-6-phenyloctahydro-2H-[1,3]dioxino[5′,4′:4,5]benzo[1,2-d]oxazol-2-one (1.77 g, 4.31 mmol) in dry DCM (25 mL) at room temperature was added bis(2-methoxyethyl)aminosulfur trifluoride (3.81 g, 17.2 mmol). The mixture was stirred at room temperature under N2 for 20 h. The mixture was slowly diluted with saturated aqueous NaHCO3 (80 mL), extracted with EtOAc (2×50 mL). The extracts were washed with brine and dried with MgSO4. The solvents were evaporated to give the crude product. This was purified by SiO2 column, eluted with 25-35% EtOAc in hexanes to give (3aS,4S,4aR,8aR,9aS)-4-fluoro-3-(methoxy(phenyl)methyl)-6-phenyloctahydro-2H-[1,3]dioxino[5′,4′:4,5]benzo[1,2-d]oxazol-2-one (900 mg, 51%). MS m/z 436.6 (M+23, 100%); 1H NMR (400 MHz, CDCl3) δ 7.34-7.50 (m, 10H), 6.15 (s, 1H), 5.49 (s, 1H), 4.91 (dd, J=51.4 Hz, 3.0 Hz, 1H), 4.40 (d, J=5.0 Hz, 1H), 4.29 (dd, J=11.2 Hz, 4.8 Hz, 1H), 3.66 (s, 3H), 3.25-3.55 (m, 3H), 2.59-2.71 (m, 1H), 2.20-2.25 (m, 1H), 1.23-1.32 (m, 1H).

1. extractionextracted with EtOAc (2×50 mL)
2. washThe extracts were washed with brine
3. dry with materialdried with MgSO4
4. customThe solvents were evaporated
5. customto give the crude product
6. customThis was purified by SiO2 column
7. washeluted with 25-35% EtOAc in hexanes