反应详情

温度

-20 °C

9-Oxo-3-aza-spiro[5.5]undecane-3-carboxylic acid tert-butyl ester (1 g, 3.74 mmol) and cerium(III) chloride heptahydrate (1.39 g, 3.74 mmol) in methanol (40 mL) was cooled to −78° C. and sodium borohydride (141 mg, 3.74 mmol) was added in 4 portions. The mixture was warmed up to −20° C. and stirred for 30 min. Water was added and the mixture was concentrated in vacuo. The aqueous layer was extracted three times with ethyl acetate. The combined organic phase was washed with brine, dried (sodium sulfate), filtered and evaporated to give 883 mg (88%) of 9-hydroxy-3-aza-spiro[5.5]undecane-3-carboxylic acid tert-butyl ester as a colourless oil.

1. concentrationthe mixture was concentrated in vacuo
2. extractionThe aqueous layer was extracted three times with ethyl acetate
3. washThe combined organic phase was washed with brine
4. dry with materialdried (sodium sulfate)
5. filtrationfiltered
6. customevaporated