Sodium Hydroxide → cis-Rac-4-phenyl-8-(2-p-tolyl-cyclohexyl)-2,8-diaza-spiro[4.5]decan-1-one

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Reaction Steps

A mixture of rac-2-p-tolyl-cyclohexanone (410 mg, 2 mmol), rac-4-phenyl-2,8-diaza-spiro[4.5]decan-1-one (502 mg, 2 mmol) and titanium(IV) isopropoxide (810 uL, 3 mmol) were stirred at rt for 3 h. The mixture was then diluted with THF (5 mL) and then a solution of polymethylhydroxysiloxane (261 mg, 4 mmol) in THF (5 mL) was added and the resulting solution stirred at rt overnight. To this solution Na(CN)BH3 (245 mg) was added and the resulting mixture stirred at rt for 3 h. Then NaOH (3M, 10 mL) was added and the mixture stirred for 1 h. The resulting precipitate was then filtered off over celite and the filtrate was washed with brine, dried and evaporated to leave a light yellow foam. Purification by chromatography on silica gel eluting with DCM:MeOH:NH4OH (25%) (98:2:0.1 to 95:4.5:0.5) afforded the title compound (250 mg, 29%) which was obtained as a white solid. MS: m/e=403.6 (M+H).

Provenance & Evidence