反应详情

温度

25 °C

A mixture of 66.1 g. (0.25 mol.) of (±)-(6-hydroxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid and 250 ml. each of pyridine and acetic anhydride was stirred at 25°C. under N2 for 20 hours and stripped of solvent at 40°C. to give an orangebrown oil. To a suspension of this material in 500 ml. of H2O and 100 ml. of tetrahydrofuran was added 166 g. (2.0 mol.) of NaHCO3. The suspension was stirred at 25°C. for 4.0 hours, washed with ether, acidified with 2N-aqueous HCl and extracted with ether. The ether solutions were washed with saturated brine, dried over sodium sulfate and stripped of solvent to give (±)-(6-acetoxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid as an orangeish resin. Crystallization from diethyl ether petroleum ether (b.p. 30°-60°C.) gave (±)-(6-acetoxy-2,5,7,8-tetramethylchroman-2-yl)acetic acid as a granular white solid.

1. additionA mixture of 66.1 g
2. customstripped of solvent at 40°C.
3. customto give an orangebrown oil
4. additionTo a suspension of this material in 500 ml
5. washwashed with ether
6. extractionextracted with ether
7. washThe ether solutions were washed with saturated brine
8. dry with materialdried over sodium sulfate