Allyl bromide → (5R,6S)-3-allyl-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-ethyl-1-((S)-1-hydroxybutan-2-yl)piperidin-2-one

Participants

Reaction Conditions

Reaction Steps

(5R,6S)-1-((S)-1-(Tert-butyldiphenylsilyloxy)butan-2-yl)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-ethylpiperidin-2-one (421 mg, 0.639 mmol; Example 202, Step A) was azeotroped with toluene (3×). THF (1.6 mL) was added. The mixture was sparged with argon for 5 minutes and then cooled to 0° C. 1.0 M lithium diisopropylamide solution in THF (1.246 mL, 1.246 mmol) was added dropwise. After 25 minutes, allyl bromide (0.166 mL, 1.917 mmol) was added dropwise. After 20 minutes, the mixture was quenched with sat. aq. NH4Cl solution. The mixture was extracted with ethyl acetate. The organic layer was washed with sat. aq. NaCl solution, dried over Na2SO4, and concentrated. The residue was dissolved in THF (3 mL) and 1.0M tetrabutylammonium fluoride solution in THF (2.335 mL, 2.335 mmol) was added. After stirring overnight, the mixture was partitioned between 5% aq. HCl and ethyl acetate. The organic layer was washed with sat. aq. NaCl solution, dried over Na2SO4, and concentrated. The residue was purified by flash chromatography on silica gel (eluent: 20 to 50% ethyl acetate/hexanes) to afford the title compound as the more polar major diastereomer.

Provenance & Evidence