2-((3R,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-methyl-2-oxo-1-((S)-1-oxobutan-2-yl)piperidin-3-yl)acetic acid → 2-((3R,5R,6S)-5-(3-Chlorophenyl)-6-(4-chlorophenyl)-1-((2R,3S)-2-hydroxypentan-3-yl)-3-methyl-2-oxopiperidin-3-yl)acetic acid

Participants

Reaction Conditions

Reaction Steps

A solution of 2-((3R,5R,6S)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-methyl-2-oxo-1-((S)-1-oxobutan-2-yl)piperidin-3-yl)acetic acid (71 mg, 0.154 mmol) (Example 210, StepA) in THF (2 mL) was sparged with argon for 5 minutes. The mixture was cooled to 0° C. and methylmagnesium chloride, 3.0 M solution in tetrahydrofuran (0.113 ml, 0.339 mmol) was added at such a rate that the internal temperature did not get above 4° C. The mixture was stirred at 0° C. for 45 minutes. The mixture was quenched with sat. aq. NH4Cl solution and extracted with EtOAc. The combined organic layers were dried over Na2SO4, filtered and the filtrate was concentrated. The residue was purified by flash chromatography on silica gel (2×4 g stacked columns, eluent: 5 to 15% isopropanol/hexanes) to give the title compound as the more polar diastereomer.

Provenance & Evidence