Allyl bromide → (3S,5R,6S)-3-allyl-1-((S)-1-((tert-butyldiphenylsilyl)oxy)butan-2-yl)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-methylpiperidin-2-one

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of 37.3 mL (266 mmol) of diisopropylamine in dry, degassed THF (150 mL) was added 100 mL (250 mmol) of a degassed 2.5 M solution of n-butyllithium in hexanes slowly via cannula. The light yellow solution was stirred at −78° C. for 15 min, then was warmed to 0° C. and stirred for an additional 5 min. To the ice-cooled LDA solution was added a solution of 85.7 g (133 mmol) of (5R,6S)-1-((S)-1-(tert-butyldiphenylsilyloxy)butan-2-yl)-5-(3-chlorophenyl)-6-(4-chlorophenyl)-3-methylpiperidin-2-one (Example 185, Step D) in dry, degassed THF (210 mL) via cannula over a 15 min period. The dark orange solution was stirred at 0° C. for 30 min and then 34.5 mL (399 mmol) of allyl bromide was added quickly via syringe. After 20 sec, the ice bath was removed and the reaction was placed in a room temperature water bath and stirred for an additional 15 min. The reaction was quenched with saturated aq. ammonium chloride, and extracted with EtOAc (3×). The combined organic layers were dried over Na2SO4, filtered and the filtrate was concentrated. Purification of the residue by chromatography on silica gel (Biotage® Snap™ column; Biotage, LLC, Charlotte, N.C.), 6-14% EtOAc/hexanes, gradient elution) provided the title compound as a white foam.

Provenance & Evidence