反应详情

Under an argon atmosphere, tert-butyl 2,8-diazaspiro[4.5]decane-2-carboxylate hydrochloride (3.2 g) and a 10% acetic acid-anhydrous N,N-dimethylformamide (50 mL) solution of cyclohexanone (1.9 mL) were stirred at room temperature for 4 hours. To the resultant solution, sodium tiacetoxy borohydride (5.2 g) was added. The reaction solution was stirred at room temperature for 15 hours. To the reaction solution, water (100 mL) and an aqueous 1N-sodium hydroxide solution (100 mL) were added. The aqueous layer was extracted twice with ethyl acetate. The organic layers were combined, washed with saturated saline and then dried over anhydrous sodium sulfate. The anhydrous sodium sulfate was removed by filtration and the solvent was concentrated under reduced pressure. The residue was purified by silica gel chromatography (ethyl acetate:methanol=1:0→8:2) to obtain the title compound having the following physical properties (3.7 g).

1. extractionThe aqueous layer was extracted twice with ethyl acetate
2. washwashed with saturated saline
3. dry with materialdried over anhydrous sodium sulfate
4. customThe anhydrous sodium sulfate was removed by filtration
5. concentrationthe solvent was concentrated under reduced pressure
6. customThe residue was purified by silica gel chromatography (ethyl acetate:methanol=1:0→8:2)