反应详情

A reflux condenser equipped with a Dean-Stark water separator was attached to a round bottom flask containing ethyl 4-cyclohexanonecarboxylate (5 ml, 31.4 mmol), ethylene glycol (1.93 ml, 34.5 mmol), p-toluenesulfonic acid monohydrate (200 mg, 1.05 mmol), and benzene (30 ml). The mixture was heated under reflux for 3 hours. To the reaction mixture, triethylamine (181 μl, 1.3 mmol) was added and the mixture was concentrated. A tetrahydrofuran solution of the resultant crude substance was added to a tetrahydrofuran (30 ml) suspension of lithium aluminum hydride (1.31 g, 34.5 mmol) at 0° C. After the mixture was stirred at room temperature for 7 hours, water (1.3 ml), a 5N aqueous sodium hydroxide solution (1.3 ml), and water (3.9 ml) were sequentially added to the mixture at 0° C. After dried over sodium sulfate, the mixture was filtrated. The filtrate was concentrated under reduced pressure and purified by silica gel column chromatography (elution solvent: ethyl acetate/heptane=1/2, 1/1, 2/1) to obtain the title compound (4.6 g, yield: 85.1%) as a colorless oil.

1. customseparator was attached to a round bottom flask
2. temperatureThe mixture was heated
3. temperatureunder reflux for 3 hours
4. concentrationthe mixture was concentrated
5. dry with materialAfter dried over sodium sulfate
6. filtrationthe mixture was filtrated
7. concentrationThe filtrate was concentrated under reduced pressure
8. custompurified by silica gel column chromatography (elution solvent: ethyl acetate/heptane=1/2, 1/1, 2/1)