反应详情

温度

22.5 °C

A 500-ml four-mouth flask equipped with a thermometer, dropping funnel, condenser, and stirrer was charged with 13.0 g (0.1 mol) of (S)-2-methoxycyclohexanol having an optical purity of 99.8% ee, 7 g of dichloromethane, and 30 g of 10% aqueous solution of sulfuric acid (30 mmol). The reactants were stirred at 20-25° C. The flask was further charged with 60 g of aqueous solution of sodium hypochlorite containing 12.1% effective chlorine over about 1 hour. Stirring was continued for 30 minutes. The reaction solution was analyzed by gas chromatography to confirm that the peak due to (S)-2-methoxycyclohexanol had disappeared. The reaction solution was given 2 g of sodium hydrogensulfite with stirring. It was confirmed that the reaction solution did not change potassium iodide starch paper into purple any longer. The reaction solution was extracted twice with 200 g of dichloromethane. The dichloromethane layers were combined together and washed with 30 g of 30% aqueous solution of sodium carbonate. After stirring at 20-25° C. for 1 hour, it was confirmed that the water layer had a pH higher than 7.5. The water layer was discharged, and the dichloromethane layer was washed with saturated aqueous solution of sodium chloride. Upon concentration and distillation, there was obtained 11.5 g (90 mmol) of (S)-2-methoxycyclohexanone. The chemical purity of this compound was 99.6%. One gram of this compound was placed in a glass ample and sealed, with the atmosphere therein replaced with argon. The ample was heated at a prescribed temperature for 60 hours. After cooling to room temperature, the ample was opened and the content was tested for optical purity. The results are shown in Table 2.

1. stirringStirring
2. stirringwith stirring
3. extractionThe reaction solution was extracted twice with 200 g of dichloromethane
4. washwashed with 30 g of 30% aqueous solution of sodium carbonate
5. stirringAfter stirring at 20-25° C. for 1 hour
6. washthe dichloromethane layer was washed with saturated aqueous solution of sodium chloride
7. concentrationUpon concentration and distillation