(2S)-2-methoxycyclohexan-1-one

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Reaction was carried out in the same manner as in Example 16. After the peak due to (S)-2-methoxycyclohexanol had disappeared, the reaction solution was given 2 g of sodium hydrogensulfite with stirring so that the reaction solution did not change potassium iodide starch paper into purple any longer. The reaction solution was extracted twice with 100 g of dichloroethane. The dichloroethane layers were combined together and washed with a saturated aqueous solution of sodium chloride. After concentration and distillation in the same manner as in Example 1, there was obtained 10.9 g (85 mmol) of (S)-2-methoxycyclohexanone having a chemical purity of 99.4% and an optical purity of 99.5% ee (measured immediately after distillation). As in Example 3, this product was sealed in a glass ample, with the atmosphere therein replaced with argon. The glass ample was heated at a prescribed temperature for 20 hours. After cooling to room temperature, the ample was opened and the content was tested for optical purity. The results are shown in Table 3. Reaction The reaction solution was extracted twice with 100 g of dichloroethane washed with a saturated aqueous solution of sodium chloride After concentration and distillation in the same manner as in Example 1

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Reaction was carried out in the same manner as in Example 16. After the peak due to (S)-2)-methoxycyclohexanol had disappeared, the reaction solution was given 2 g of sodium hydrogensulfite with stirring so that the reaction solution did not change potassium iodide starch paper into purple any longer. The reaction solution was adjusted to pH 2 or below with 10% sulfuric acid, followed by stirring at 20-25° C. for 1 hour. The reaction solution was adjusted to pH 7.5-8 with an aqueous solution of sodium carbonate, followed by stirring at 20-25° C. for 1 hour. The reaction solution was adjusted again to pH 2 or below with 10% sulfuric acid, followed by stirring at 20-25° C. for 2 hours. The reaction solution was extracted three times with 100 g of toluene. The toluene layers were combined together and washed with a saturated aqueous solution of sodium chloride. After concentration and distillation in the same manner as in Example 1, there was obtained 10.3 g (80 mmol) of (S)-2-methoxycyclohexanone having a chemical purity of 99.3% and an optical purity of 99.6% ee. This product was heated at 60° C. for 48 hours in the same manner as in Example 16; it decreased in optical purity to 99.0% ee. Reaction by stirring at 20-25° C. for 1 hour by stirring at 20-25° C. for 1 hour by stirring at 20-25° C. for 2 hours The reaction solution was extracted three times with 100 g of toluene washed with a saturated aqueous solution of sodium chloride After concentration and distillation in the same manner as in Example 1

反応条件: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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. Stirring with stirring The reaction solution was extracted twice with 200 g of dichloromethane washed with 30 g of 30% aqueous solution of sodium carbonate After stirring at 20-25° C. for 1 hour the dichloromethane layer was washed with saturated aqueous solution of sodium chloride Upon concentration and distillation

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Reaction was carried out in the same manner as in Example 16. After the peak due to (S)-2)-methoxycyclohexanol had disappeared, the reaction solution was given 2 g of sodium hydrogensulfite with stirring so that the reaction solution did not change potassium iodide starch paper into purple any longer. The reaction solution was adjusted to pH 2 or below with 10% sulfuric acid, followed by stirring at 20-25° C. for 1 hour. The reaction solution was adjusted to pH 7.5-8 with an aqueous solution of sodium carbonate, followed by stirring at 20-25° C. for 1 hour. The reaction solution was adjusted again to pH 2 or below with 10% sulfuric acid, followed by stirring at 20-25° C. for 2 hours. The reaction solution was extracted three times with 100 g of toluene. The toluene layers were combined together and washed with a saturated aqueous solution of sodium chloride. After concentration and distillation in the same manner as in Example 1, there was obtained 10.3 g (80 mmol) of (S)-2-methoxycyclohexanone having a chemical purity of 99.3% and an optical purity of 99.6% ee. This product was heated at 60° C. for 48 hours in the same manner as in Example 16; it decreased in optical purity to 99.0% ee. Reaction by stirring at 20-25° C. for 1 hour by stirring at 20-25° C. for 1 hour by stirring at 20-25° C. for 2 hours The reaction solution was extracted three times with 100 g of toluene washed with a saturated aqueous solution of sodium chloride After concentration and distillation in the same manner as in Example 1

反応条件: temp:0.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a 1 liter 4-necked flask, (1S,2S)-2-methoxycyclohexanol (53.57 g,0.411 mol) and methylene chloride (250 ml) were placed, and subsequently, 2,2,6,6-tetramethyl-1-piperidinyloxy free radical(1.28 g, 0.008 mol), potassium bromide (1.47 g, 0.0123 mol), and 8%-sodium hydrogencarbonate solution (52 ml, 0.0494 mol) were added and cooled to 0° C. To this mixture, 3.1N sodium hypochlorite solution (254 ml, 0.787 mol) was added dropwise over a period of 6 hours while maintaining a temperature of 0° C. to 5° C. After the disappearance of the raw material (1S,2S)-2-methoxycyclohexanol was confirmed by gas chromatography, sodium sulfite (5.36 g, 0.0425 mol) was added to the mixture to perform fractionation. Distillation was then performed, and the aqueous phase was subjected to extraction with two 25 ml portions of methylene chloride. The solvent was distilled off under a reduced pressure, and further distillation was performed to obtain (2S) -2-methoxycyclohexanone (51.67 g). The yield was 95%, the boiling point and optical purity of the product were 84° C./24 mmHg and 100%e.e., respectively. Incidentally, the gas chromatography for confirming the disappearance of (1S,2S)-2-methoxycyclohexanol was performed using the following apparatus and conditions. while maintaining a temperature of 0° C. to 5° C was added to the mixture Distillation the aqueous phase was subjected to extraction with two 25 ml portions of methylene chloride The solvent was distilled off under a reduced pressure, and further distillation

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Reaction was carried out in the same manner as in Example 16. After the peak due to (S)-2-methoxycyclohexanol had disappeared, the reaction solution was given 2 g of sodium hydrogensulfite with stirring so that the reaction solution did not change potassium iodide starch paper into purple any longer. The reaction solution was extracted twice with 100 g of dichloroethane. The dichloroethane layers were combined together and washed with a saturated aqueous solution of sodium chloride. After concentration and distillation in the same manner as in Example 1, there was obtained 10.9 g (85 mmol) of (S)-2-methoxycyclohexanone having a chemical purity of 99.4% and an optical purity of 99.5% ee (measured immediately after distillation). As in Example 3, this product was sealed in a glass ample, with the atmosphere therein replaced with argon. The glass ample was heated at a prescribed temperature for 20 hours. After cooling to room temperature, the ample was opened and the content was tested for optical purity. The results are shown in Table 3. Reaction The reaction solution was extracted twice with 100 g of dichloroethane washed with a saturated aqueous solution of sodium chloride After concentration and distillation in the same manner as in Example 1

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: Reaction was carried out in the same manner as in Example 16. After the peak due to (S)-2)-methoxycyclohexanol had disappeared, the reaction solution was given 2 g of sodium hydrogensulfite with stirring so that the reaction solution did not change potassium iodide starch paper into purple any longer. The reaction solution was adjusted to pH 2 or below with 10% sulfuric acid, followed by stirring at 20-25° C. for 1 hour. The reaction solution was adjusted to pH 7.5-8 with an aqueous solution of sodium carbonate, followed by stirring at 20-25° C. for 1 hour. The reaction solution was adjusted again to pH 2 or below with 10% sulfuric acid, followed by stirring at 20-25° C. for 2 hours. The reaction solution was extracted three times with 100 g of toluene. The toluene layers were combined together and washed with a saturated aqueous solution of sodium chloride. After concentration and distillation in the same manner as in Example 1, there was obtained 10.3 g (80 mmol) of (S)-2-methoxycyclohexanone having a chemical purity of 99.3% and an optical purity of 99.6% ee. This product was heated at 60° C. for 48 hours in the same manner as in Example 16; it decreased in optical purity to 99.0% ee. Reaction by stirring at 20-25° C. for 1 hour by stirring at 20-25° C. for 1 hour by stirring at 20-25° C. for 2 hours The reaction solution was extracted three times with 100 g of toluene washed with a saturated aqueous solution of sodium chloride After concentration and distillation in the same manner as in Example 1

反応条件: temp:22.51; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: 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. Stirring with stirring The reaction solution was extracted twice with 200 g of dichloromethane washed with 30 g of 30% aqueous solution of sodium carbonate After stirring at 20-25° C. for 1 hour the dichloromethane layer was washed with saturated aqueous solution of sodium chloride Upon concentration and distillation