Trifluoroacetic acid → HCID 68000991, compound

Participants

Reaction Steps

(5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(5-chloropyridin-2-yl)-1-(2,4-dimethoxybenzyl)-3-methylpiperidin-2-one (3.6 g, 6.85 mmol, mixture of C-3 epimers, Example 124, Step B) was dissolved in TFA (26.4 mL, 343 mmol) and the reaction was heated to 70° for 1.5 h. It was then cooled to ambient temperature and the TFA was removed by concentration under reduced pressure. The product was azeotroped with heptanes, dissolved in DCM and the organic layer was washed with sat. aq. NaHCO3 solution and sat. NaCl solution. Purification by flash chromatography on silica gel (eluent: 35 to 45% EtOAc/hexanes which had been NH3 sparged, gradient elution) provided the title compound as the more polar isomer as a white solid: (Rf in 75% EtOAc/Hexanes=0.44).

Provenance & Evidence