Citric Acid → [(3r,5r,6s)-1-[(2s)-1-Tert-Butoxy-1-Oxobutan-2-Yl]-5-(3-Chlorophenyl)-6-(4-Chlorophenyl)-2-Oxopiperidin-3-Yl]acetic Acid

Participants

Reaction Steps

To a rapidly stirring solution of 842 mg (1.67 mmol) of tert-butyl (2S)-2-((3S,5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-2-oxopiperidin-1-yl) butanoate (Example 1, Step G) in a mixture of 7 mL of water, 5 mL of acetonitrile and 5 mL of CCl4 was added sodium periodate (1.43 g, 6.70 mmol), followed by ruthenium(III) chloride hydrate (37.8 mg, 0.168 mmol). After being stirred vigorously for 18 h, the reaction was acidified (10% citric acid) and diluted with EtOAc. The reaction mixture was filtered through celite and the filtrate was extracted with EtOAc. The combined organic layers were washed with sat. NaCl solution, dried over Na2SO4, filtered and the filtrate was concentrated under reduced pressure. The residue was purified by reversed phase preparatory HPLC (Gemini™ Prep C18 5 μm column, Phenomenex, Torrance, Calif.; eluent: 60 to 80% acetonitrile +0.1% TFA in water +0.1% TFA, gradient elution) to give the title compound as a white solid.

Provenance & Evidence