Cyclohexanone → Tert-butyl 8-cyclohexyl-2,8-diazaspiro[4.5]decane-2-carboxylate

Participants

Reaction Steps

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).

Provenance & Evidence