Reaction Steps
To a suspension of (3aS,4R,5R,6S,7aS)-3-acetyl-6-(difluoromethyl)-2-oxooctahydrobenzo[d]oxazole-4,5-diyl dibenzoate (892 mg, 1.89 mmol) in MeOH (20 mL) was added K2CO3 (781 mg, 5.66 mmol). The mixture was stirred at room temperature for 2 h. The solvent was evaporated and the residue was purified by SiO2 column, eluted with 5%-10% MeOH in DCM to give (3aR,4R,5R,6S,7aS)-6-(difluoromethyl)-4,5-dihydroxyhexahydrobenzo[d]oxazol-2(3H)-one (256 mg, 69%) and N-((1S,2R,3R,4S,6S)-4-(difluoromethyl)-2,3,6-trihydroxycyclohexyl)acetamide (176 mg, 31%), both were as a white solid. (3aR,4R,5R,6S,7aS)-6-(difluoromethyl)-4,5-dihydroxyhexahydrobenzo[d]oxazol-2(3H)-one: MS m/z 246.1 (M+23, 100%); 1H NMR (400 MHz, MeOD) δ 6.18 (td, J=56.6 Hz, 1.3 Hz, 1H), 4.74-4.78 (m, 1H), 3.51 (t, J=6.9 Hz, 1H), 3.30-3.38 (m, 2H), 2.25 (dt, J=15.4 Hz, 3.2 Hz, 1H), 2.01-2.16 (m, 1H), 1.82-1.90 (m, 1H). N-((1S,2R,3R,4S,6S)-4-(difluoromethyl)-2,3,6-trihydroxycyclohexyl)acetamide: MS m/z 240.1 (M+1, 100%); 1H NMR (400 MHz, MeOD) δ 5.98 (t, J=55.1 Hz, 1H), 3.89 (br s, 1H), 3.46-3.57 (m, 2H), 3.14-3.23 (m, 1H), 2.05-2.20 (m, 1H), 2.00 (s, 3H), 1.76 (dt, J=14.2 Hz, 3.6 Hz, 1H), 1.34-1.42 (m, 1H)
