反应详情

5-Benzyloxy-2-difluoromethyl-pyran-4-one (0.47 g, 1.9 mmol) was dissolved in ethanol (15 mL) to give a slightly yellow clear solution. Ammonium hydroxide (28-30% aqueous solution, 15 mL, 235 mmol) was added at room temperature. The resulting solution was stirred at ambient temperature for 24 hours. The progress of the reaction was monitored by TLC (CH2Cl2/EtOAc, 7/3, v/v) and HPLC Method 2. Volatiles were removed in vacuo and the residue was purified by column chromatography on silica (95/5 then 85/15 CH2Cl2/MeOH, v/v) to give the title compound as a light yellow solid (0.35 g, 74%) with a HPLC purity (peak percent area) of 98.2%. 1H NMR (300 MHz, DMSO-D6) δ (ppm): 10.99 (br. s, 1H), 8.22 (s, 1H), 7.32-7.32 (m, 5H), 7.06 (s, 1H), 6.75 (t, J=55.4 Hz, 1H), 5.23 (s, 2H); MS (m/z) 252 [M+1]+, 192.2, 91.3 (100%).

1. customto give a slightly yellow clear solution
2. customVolatiles were removed in vacuo
3. customthe residue was purified by column chromatography on silica (95/5