反应详情

To 2-fluorophenylacetic acid (25 g, 0.16 mol) and methyl lactate (17 g, 0.16 mol) in THF (600 ml) was added 1,3-dicyclohexylcarbodiimide (34 g, 0.16 mol) and 4-dimethylaminopyridine (0.99 g, 8.1 mmol) at 5° C. The mixture was allowed to warm to room temperature and stirred under nitrogen overnight. The solvent was removed in vacuo, then the residue was taken up in diethyl ether (300 ml), and the resulting slurry was filtered to remove insoluble material. The filtrate was concentrated in vacuo, and the residual oil was dissolved in potassium tert-butoxide solution (162 ml of a 1.0 M solution in tert-butanol). The mixture was stirred at reflux for 16 h and was allowed to cool to room temperature. Water (300 ml) was added, and the solution was washed with diethyl ether (2×100 ml). The aqueous solution was acidified to pH 1 with 5 N hydrochloric acid. The product formed an immiscible oil, which solidified upon standing. This was collected by filtration, washed with water and dried at 50° C., yielding 3-(2-fluorophenyl)-4-hydroxy-5-methyl-5H-furan-2-one as a pale yellow solid (23.2 g). 1H NMR (400 MHz, CDCl3) δ 1.46 (3H, d, J=6.7 Hz), 5.00 (1H, q, J=6.7 Hz), 7.22 (2H, m), 7.39 (2H, m), 12.50 (1H, br s).

1. customThe solvent was removed in vacuo
2. filtrationthe resulting slurry was filtered
3. customto remove insoluble material
4. concentrationThe filtrate was concentrated in vacuo
5. dissolutionthe residual oil was dissolved in potassium tert-butoxide solution (162 ml of a 1.0 M solution in tert-butanol)
6. stirringThe mixture was stirred
7. temperatureat reflux for 16 h
8. temperatureto cool to room temperature
9. additionWater (300 ml) was added
10. washthe solution was washed with diethyl ether (2×100 ml)
11. customThe product formed an immiscible oil, which
12. filtrationThis was collected by filtration
13. washwashed with water
14. customdried at 50° C.