反应详情

To a solution of (±)-6-acetoxy-2-methoxy-2,5,7,8-tetramethylchroman in 2500 ml. of acetone was added 2000 ml. of H 2 O followed by 16.6 ml. of concentrated aqueous HCl. Solvent was distilled from the stirred mixture until the head temperature reached 90° centigrade. The suspension was cooled in an H 2 O bath to 50° centigrade. At 70° centigrade, 2000 ml. of acetone was added, giving a clear solution. The solution was seeded occasionally until crystallization began. After 3.5 hours, 1500 ml. of H 2 O was added and the suspension was cooled in an ice bath. The solid was removed by filtration, washed with H 2 O and dried at 50° centigrade/0.1mmHg. to give (±)-6-acetoxy-2-hydroxy-2,5,7,8-tetramethylchroman as a granular yellow-tan solid, sintering from 114 degrees centigrade, m.p. 127°-132° centigrade.

1. distillationSolvent was distilled from the stirred mixture until the head temperature
2. customreached 90°
3. temperatureThe suspension was cooled in an H 2 O bath to 50° centigrade
4. customAt 70°
5. additionof acetone was added
6. customgiving a clear solution
7. customThe solution was seeded occasionally until crystallization
8. additionof H 2 O was added
9. temperaturethe suspension was cooled in an ice bath
10. customThe solid was removed by filtration
11. washwashed with H 2 O
12. customdried at 50° centigrade/0.1mmHg