反应详情

To a solution of 2,8-dimethyl-1-oxa-8-azaspiro[4,5]-decan-3-one (200 mg) in 7 ml ethanol, was added 25 mg sodium borohydride at room temperature, and the mixture was stirred at room temperature for two hours. The reaction mixture was cooled in an ice-water bath, acidified by addition of 6N-HCl (to about pH 4), and stirred for about 20 minutes with the ice-water bath removed. Ethanol was distilled off under reduced pressure, and the residue was purified by silica gel column chromatography by using, as eluent, a mixed solvent of chloroform/methanol/conc. ammonia (5:1:0.1 by volume), giving 200 mg of 3-hydroxy-2,8-dimethyl-1-oxa-8-azaspiro[4,5]decane as oil. It was dissolved in ether, and ethanolic hydrogen chloride was added to this solution, thus giving its hydrochloride as white crystals.

1. temperatureThe reaction mixture was cooled in an ice-water bath
2. customremoved
3. distillationEthanol was distilled off under reduced pressure
4. customthe residue was purified by silica gel column chromatography