1-Boc-2-phenyl-piperidin-4-one → (+/-)-tert-butyl (2R,4S)-4-methyl-2-phenylpiperidin-4-ol-1-carboxylate

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Reaction Steps

Methylmagnesium bromide (3 M solution in ether, 1.2 mL, 3.6 mmol) was added to a solution of tert-butyl 4-oxo-2-phenylpiperidine-1-carboxylate (328 mg, 1.2 mmol), in tetrahydrofuran (20 mL) at 0° C. and the resulting mixture was stirred at this temperature one hour. The reaction mixture was then quenched with saturated aqueous ammonium chloride solution (20 mL) and diluted with ethyl acetate (80 mL). The organic portion was separated, washed with water, then brine solution, dried over sodium sulfate, filtered and concentrated. The residue purified by silica gel chromatography (25% to 70% ethyl acetate in hexane gradient) to give the first eluting isomer assigned as (±)-tert-butyl (2R,4S)-4-methyl-2-phenylpiperidin-4-ol-1-carboxylate (100 mg, 29% yield), LC-MS for C17H25NO3: 292 (MH+); and the second eluting isomer assigned as (±)-tert-butyl (2R,4R)-4-methyl-2-phenylpiperidin-4-ol-1-carboxylate (120 mg, 35% yield), MS (EI) for C17H25NO3: 292 (MH+).

Provenance & Evidence