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

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Reaction Steps

To a solution of 10.2 g (21.4 mmol) of (2S)-tert-butyl 2-(2S,3R)-3-(3-chlorophenyl)-2-(4-chlorophenyl)-5-methyl-6-oxopiperidin-1-yl)butanoate (Example 66, Step B, mixture of diastereomers) and allyl bromide (7.24 mL, 86 mmol) in THF (210 mL) was added LHMDS, (1.0M solution in THF; 64.2 mL, 64.2 mmol) at R.T. Let it stir at R.T. for 5 min. Then the reaction mixture was heated at 50° C. for 3 h. Sat. aq. NH4Cl solution was added and the mixture was extracted with CH2Cl2. The combined organic layers were washed with water and sat. aq. NaCl solution, dried over MgSO4, filtered and the filtrate was concentrated under reduced pressure. The residue was purified by chromatography, eluting with a gradient of 0% to 20% EtOAc in hexane, to provide the title compound as a mixture of stereoisomers at C-3.

Provenance & Evidence