反应详情

To a stirred solution of 0.44 g (0.97 mmol) of 23 in 7 mL of MeOH and 7 mL of THF was added 1.5 mL (1.5 mmol) of 1 N NaOH solution. The resulting solution was stirred at room temperature for 4 h. The solvent was removed in vacuo, and the residue was diluted with 10 mL of H2O, acidified to pH˜3 with 1N HCl, and extracted with 30 mL of EtOAc. The organic layer was dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by flash chromatography (EtOAc/Hex 1:1) to afford 0.36 g (87%) of 8: mp 238-240° C.; 1H NMR (400 MHz, DMSO-d6) δ 12.5 (brs, 1H), 12.04 (s, 1H), 8.00 (s, 1H), 7.93 (d, J=7.4 Hz, 2H), 7.80 (s, 1H), 7.70 (d, J=8.2 Hz, 1H), 7.59-7.48 (m, 9H), 7.38 (t, J=7.1 Hz, 1H), 7.07 (d, J=1.2 Hz, 1H), 3.69 (s, 2H); 13C NMR (100 MHz, CDCl3) δ 186.6, 172.0, 147.4, 141.6, 141.0, 136.3, 132.6, 132.2, 131.9, 131.4, 130.4, 129.2, 129.1, 128.8, 128.3, 125.6, 125.4, 120.5, 99.3, 34.1; IR (KBr) cm−1 3417, 3054, 1713, 1596.

1. customThe solvent was removed in vacuo
2. additionthe residue was diluted with 10 mL of H2O
3. extractionextracted with 30 mL of EtOAc
4. dry with materialThe organic layer was dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was purified by flash chromatography (EtOAc/Hex 1:1)