Hydrochloric Acid → (5R)-1-Allyl-5-[4'-(trifluoromethoxy)-1,1'-biphenyl-4-yl]-2-pyrrolidinone

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Reaction Conditions

Reaction Steps

Under argon, KOtBu (0.64 g, 5.7 mmol) is suspended, in a Schlenk tube which had been dried by heating, in THF (5 ml, anhydrous). At 0° C., a solution of (4S)-N-allyl-4-hydroxy-4-[4′-(trifluoromethoxy)-1,1′-biphenyl-4-yl]butanamide (XVI-1) (0.99 g, 2.6 mmol) in THF (8 ml, anhydrous) is added dropwise. The reaction mixture is stirred at 0° C. for 1 h and a solution of tosyl chloride (0.52 g, 2.7 mmol) in THF (5 ml, anhydrous) is then added dropwise over a period of 20 min. The mixture is stirred at 0° C. for 2 h and at room temperature for 16 h. For work-up, the mixture is admixed with water, adjusted to pH 5 using HCl and extracted with ethyl acetate. The combined organic phases are dried (Na2SO4) and concentrated. The residue (0.85 g, content: 81%, HPLC, 100% method) is further purified by flash chromatography (mobile phase: ethyl acetate/petroleum ether (40/60), 1:1).

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