反应详情

温度

55 °C

D(+)-10-Camphorsulfonic acid (5.1 g, 22 mmol), 4-fluoro-2,6-bis(hydroxymethyl)phenol (74.5 g, 432 mmol), and 2,2-dimethoxypropane (90 mL, 734 mmol) were dissolved in acetone. To the solution was added 45 g of 4 Å molecular sieves. The resulting suspension was heated to 55° C. for 1 h and then cooled to rt. The mixture was neutralized with aqueous NaHCO3 (sat) and diluted with ethyl acetate. Solids were removed by filtration. The solvent volume was reduced in vacuo. Ethyl acetate and aqueous NaHCO3 (sat) were added, and the layers were partitioned. The organic phase was washed with brine, dried over magnesium sulfate, filtered, and concentrated in vacuo. Crude (6-fluoro-2,2-dimethyl-4H-1,3-benzodioxin-8-yl)methanol was isolated as an orange oil (91.7 g, 432 mmol, 100%). (17.2 g, 86.6 mmol, 91% yield). 1H NMR (400 MHz, CDCl3): δ 7.01 (dd, 1H), 6.79 (dd, 1H), 5.20 (t, 1H), 4.77 (s, 2H), 4.40 (d, 2H), 1.42 (s, 6H); GCMS for C11H13FO3: 212 (M+)

1. additionTo the solution was added 45 g of 4 Å molecular sieves
2. temperaturecooled to rt
3. customSolids were removed by filtration
4. additionEthyl acetate and aqueous NaHCO3 (sat) were added
5. customthe layers were partitioned
6. washThe organic phase was washed with brine
7. dry with materialdried over magnesium sulfate
8. filtrationfiltered
9. concentrationconcentrated in vacuo