反应详情

Methanesulfonic acid (0.8 mL) was added to a solution of tert-butyl 3-isopropoxy-4,4-dimethoxypiperidine-1-carboxylate obtained in Example (147b) (248 mg, 0.817 mmol) in acetone (3 mL). The mixture was stirred at room temperature overnight and further stirred at 50° C. for 35 minutes. Following cooling, saturated aqueous sodium bicarbonate solution was added to the reaction solution, and the organic substance was extracted with ethyl acetate. The organic layer was dried over magnesium sulfate, and then the solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate) to obtain 111 mg of the title compound as a colorless oily substance (53%).

1. stirringfurther stirred at 50° C. for 35 minutes
2. temperatureFollowing cooling
3. extractionthe organic substance was extracted with ethyl acetate
4. dry with materialThe organic layer was dried over magnesium sulfate
5. customthe solvent was evaporated under reduced pressure
6. customThe resulting residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate)