Methyl iodide → (2S)-tert-butyl 2-((2S,3R)-3-(3-chlorophenyl)-2-(4-chlorophenyl)-5-methyl-6-oxopiperidin-1-yl)butanoate

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Reaction Steps

To a solution of 11.2 g (24.2 mmol) of (S)-tert-butyl 2-((2S,3R)-3-(3-chlorophenyl)-2-(4-chlorophenyl)-6-oxopiperidin-1-yl)butanoate (Example 66, Step A) and iodomethane (1.813 mL, 29.1 mmol) in THF (120.0 mL) was added a lithium bis(trimethylsilyl)amide, (1M solution in THF; 26.6 mL, 26.6 mmol) at −78° C. The reaction was allowed to warm to R.T., then was quenched (sat. aqueous NH4Cl) and extracted (2×EtOAc). The combined organic layers were washed with water and sat. aq. NaCl solution, dried over Na2SO4, filtered and the filtrate was concentrated under reduced pressure. The residue was absorbed onto a plug of silica gel and purified by chromatography on silica gel, eluting with a gradient of 10% to 30% EtOAc in hexane, to provide the title compound as a mixture of stereoisomers.

Provenance & Evidence