Reaction Steps
To a solution of (3 aS,4S,5R,6R,7aS)-4-fluoro-6-(hydroxymethyl)-2-(methylthio)-3a,4,5,6,7,7a-hexahydrobenzo[d]oxazol-5-ol (50 mg, 0.21 mmol) in EtOH (3 mL) was added azetidine hydrochloride (100 mg, 1.06 mmol). The mixture was heated at reflux for 17 h. After cooling, solid NaHCO3 (100 mg, 1.19 mmol) was added and stirred for 10 min. Solvent was evaporated and the residue was purified by silica gel column chromatography, eluted with 5%-10% 2 M NH3 MeOH solution in DCM to give the product (3aS,4S,5R,6R,7aS)-2-(azetidin-1-yl)-4-fluoro-6-(hydroxymethyl)-3a,4,5,6,7,7a-hexahydrobenzo[d]oxazol-5-ol (31.4 mg, 60%) as a white solid. MS m/z 245.1 (M+1, 100%); 1H NMR (400 MHz, MeOD) δ 4.57-4.61 (m, 1H), 4.58 (ddd, J=52.8 Hz, 3.7 Hz, 1.6 Hz, 1H), 4.02 (t, J=7.6 Hz, 4H), 3.85 (ddd, J=26.1 Hz, 7.1 Hz, 3.8 Hz, 1H), 3.66-3.73 (m, 2H), 3.49 (ddd, J=30.2 Hz, 10.0 Hz, 1.5 Hz, 1H), 2.27-2.38 (m, 3H), 2.01-2.09 (m, 1H), 1.73-1.81 (m, 1H); 13C NMR (100 MHz, MeOD) δ 165.85, 93.17 (d, J=178.6 Hz), 80.71, 70.65 (d, J=19.1 Hz), 64.45 (d, J=17.3 Hz), 63.94, 51.87, 35.47 (d, J=5.8 Hz), 28.39, 17.77.
