Trichloroisocyanuric Acid → (R)-tert-butyl 3-((S)-2-(3-chlorophenyl)-6-oxotetrahydro-2H-pyran-2-yl)piperidine-1-carboxylate

Participants

Reaction Steps

To a stirred solution of (R)-tert-butyl 3-((S)-1-(3-chlorophenyl)-1,5-dihydroxypentyl)piperidine-1-carboxylate (200 mg, 0.5 mmol) in acetone (3 mL) maintained at 0° C. was added an 15% aq NaHCO3 (2 mL), followed by solid NaBr (10.3 mg, 0.1 mmol) and TEMPO (1.56 mg, 0.01 mmol). Trichloroisocyanuric acid (231 mg, 1 mmol) was then slowly added at 0° C. The mixture was warmed to rt, stirred for 3 h and treated with 2-propanol (0.5 mL). The mixture was filtered through celite and the filtrate was concentrated in vacuo. The residue was partitioned between water and EtOAc and the aqueous phase was extracted with EtOAc (3×20 mL). The organic layers were combined, washed with brine, dried over Na2SO4 and concentrated under reduced pressure to provide (R)-tert-butyl 3-((S)-2-(3-chlorophenyl)-6-oxotetrahydro-2H-pyran-2-yl)piperidine-1-carboxylate (160 mg, 81%). 1H NMR (400 MHz, CDCl3): 1.12-1.45 (m, 3H), 1.46 (s, 9H), 1.58-1.81 (m, 6H), 2.22 (m, 2H), 2.42 (m, 2H), 2.56 (m, 2H), 4.05 (m, 1H), 4.36 (m, 1H), 7.16 (m, 1H), 7.27-7.32 (s, 1H). MS (E/Z): 394 (M+H+).

Provenance & Evidence