Pyridine 4-methylbenzene-1-sulfonate → (5R,6S)-1-((S)-1-(tert-butyldiphenylsilyloxy)butan-2-yl)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-hydroxypiperidin-2-one

Participants

Reaction Conditions

Reaction Steps

(5R,6S)-1-((S)-1-(Tert-butyldiphenylsilyloxy)butan-2-yl)-5-(3-chlorophenyl)-6-(4-chlorophenyl)piperidin-2-one (1.100 g, 1.744 mmol; Example 185, Step C) was dissolved in THF (8.72 mL) and sparged with argon for 5 minutes. The mixture was cooled to −78° C. and 1.0 M lithium bis(trimethylsilyl)amide solution in THF (2.093 mL, 2.093 mmol) was added dropwise. After 30 minutes, peroxybis(trimethylsilane) (0.413 mL, 1.918 mmol) was added dropwise. After 1 hour, the cooling bath was removed. After stirring overnight, the mixture was quenched with sat. aq. NH4Cl solution and extracted with ethyl acetate. The organic layer was washed with sat. aq. NaCl solution, dried over Na2SO4, and concentrated. The residue was dissolved in EtOH (14 mL) and pyridine p-toluenesulfonate (131 mg, 0.523 mmol) was added. After 1 hour, the mixture was basified with sat. aq. NaHCO3 solution. The mixture was partitioned between ethyl acetate and water. The organic layer was washed with sat. aq. NaCl solution, dried over Na2SO4, and concentrated. The residue was purified by flash chromatography on silica gel (40 g column, eluent: 5 to 50% ethylacetate/hexanes) to afford the title compound.

Provenance & Evidence