Allyl bromide → (5R,6S)-3-allyl-1-((S)-1-((tert-butyldiphenylsilyl)oxy)butan-2-yl)-5-(3-chlorophenyl)-6-(5-chloropyridin-2-yl)-3-methylpiperidin-2-one

Participants

Reaction Conditions

Reaction Steps

To a solution of 2.95 g (4.57 mmol) of (5R,6S)-1-((S)-1-(tert-butyldiphenylsilyloxy)butan-2-yl)-5-(3-chlorophenyl)-6-(5-chloropyridin-2-yl)-3-methylpiperidin-2-one (Example 121, Step J) and 7.91 mL (91.0 mmol) of allyl bromide in dry, degassed THF (22 mL) was added 68.6 mL (68.6 mmol) of a 1 M solution of lithium bis(trimethylsilyl)amide in THF slowly via syringe over 6 min at room temperature. After 10 min, the orange solution was warmed to 50° C. and stirred for 24 h. At this time, 11.4 mL (11.4 mmol) of a 1 M solution of lithium bis(trimethylsilyl)amide in THF and 790 μL (0.79 mmol) of allyl bromide were added. The reaction was stirred for an additional 6.25 h at 50° C., and then was cooled to room temperature and quenched with saturated aqueous ammonium chloride. The mixture was extracted with EtOAc (3×), and the combined organic layers were dried over Na2SO4, filtered and the filtrate was concentrated. Purification of the residue by flash chromatography on silica gel (2 to 25% EtOAc/hexanes, gradient elution) provided the title compound (mixture of C-3 epimers) as a light yellow solid.

Provenance & Evidence