反应详情

50 ml of a 3N aqueous sodium hydroxide solution was added to a solution of 5 g of methyl 1-methyl-4-oxo-1-cyclohexanecarboxylate, which is disclosed in a literature [T. Sohda, K. Meguro, and Y. Kawamatsu, Chem. Pharm. Bull., 32, 2267-2278 (1984)], in 150 ml of methanol. The resultant solution was reacted for 2 hours, while it was refluxed. After reaction, 2N hydrochloric acid was added to the solution, acidifying the solution. The solution was extracted five times with 50 ml of ethyl acetate. The organic layer obtained was washed three times with an aqueous sodium chloride solution and was then dried over magnesium sulfate. Thereafter, the solvent was removed in vacuo. The oily substance obtained was subjected to column chromatography using 50 g of silica gel. From the fraction eluted with hexane and ethyl acetate=2:1, the solvent was removed in vacuo, yielding 4.1 g of 1-methyl-4-oxo-1-cyclohexanecarboxyic acid as a colorless oil, which had the following physiochemical properties:

1. temperaturewas refluxed
2. additionwas added to the solution
3. extractionThe solution was extracted five times with 50 ml of ethyl acetate
4. customThe organic layer obtained
5. washwas washed three times with an aqueous sodium chloride solution
6. dry with materialwas then dried over magnesium sulfate
7. customThereafter, the solvent was removed in vacuo
8. customThe oily substance obtained
9. washFrom the fraction eluted with hexane and ethyl acetate=2:1
10. customthe solvent was removed in vacuo