Allyl iodide → (S)-4-benzyl-3-(2-(4-fluorophenyl)pent-4-enoyl)-2-oxazolidinone

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Reaction Steps

Alternately, combine (S)-4-benzyl-3-(4-fluorophenyl)acetyl-2-oxazolidinone (43.08 g, 426 mmol) and tetrahydrofuran (450 ml). Cool in a dry-ice acetone bath. Add dropwise a solution of sodium hexamethyldisilazide (153.0 ml, 1 M in tetrahydrofuran, 137.5 mmol). After 40 minutes, add a solution of allyl iodide (39.0 ml, 426 mmol) and replace the bath with a dry-ice/carbon tetrachloride bath. After 1.5 hours, quench the reaction by the addition of a saturated aqueous solution of ammonium chloride, add diethyl ether (200 ml), and stir. After about 30 minutes, separate the layers and extract the aqueous layer twice with diethyl ether. Dry the combined organic layers over MgSO4, filter, and evaporate in vacuo to give a residue. Dry the residue in a vacuum, dissolve in ethyl acetate (about 400 ml), and extract with a saturated aqueous sodium thiosulfate solution. Dry the organic layer over MgSO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting with 13% ethyl acetate/hexane to give (S)-4-benzyl-3-(2-(4-fluorophenyl)pent-4-enoyl)-2-oxazolidinone.

Provenance & Evidence