To a solution of 5.11 g of 2,8-dimethylnonan-5-one (b.p.: 103°-105° C./19 mmHg, prepared by oxidizing 2,8-dimethylnonan-5-ol with a bleaching powder; 2,8-dimethylnonan-5-ol was prepared by reaction of ethyl formate and isoamylmagnesium bromide) in 20 ml of ethanol were successively added an aqueous solution of 3.47 of hydroxylamine hydrochloride in 6 ml of water and a solution of 4.77 g of potassium hydroxide in 6 ml of water. The mixture was heated under reflux. The reaction mixture was then poured into 150 ml of ice-containing water. The aqueous mixture was made acidic by addition of 2N hydrochloric acid and extracted with benzene. The organic layer was washed with saturated aqueous sodium chloride, dried over anhydrous sodium sulfate, and evaporated under reduced pressure to remove the solvent. There was obtained 5.21 g of 2,8-dimethylnonan-5-one oxime as a pale brown oil, yield: 93.7%.
