反应详情

A mixture of 1 g of 4-hydroxy-2-methyl-2-(4-nitrophenoxymethyl)chroman (prepared as described in Preparation 2), 70 mg of p-toluenesulfonic acid monohydrate and 10 ml of benzene was heated under reflux for 45 minutes. At the end of this time, the reaction mixture was washed with a saturated aqueous solution of sodium bicarbonate and then with a saturated aqueous solution of sodium chloride, after which it was dried over anhydrous magnesium sulfate. The solvent was then distilled off under reduced pressure. The residue was subjected to silica gel column chromatography eluted with a 20:1 by volume mixture of hexane and ethyl acetate, to afford 800 mg of the title compound as a pale yellow oily substance.

1. temperaturewas heated
2. temperatureunder reflux for 45 minutes
3. washAt the end of this time, the reaction mixture was washed with a saturated aqueous solution of sodium bicarbonate
4. dry with materialwith a saturated aqueous solution of sodium chloride, after which it was dried over anhydrous magnesium sulfate
5. distillationThe solvent was then distilled off under reduced pressure
6. washeluted with a 20:1 by volume mixture of hexane and ethyl acetate