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

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Reaction Steps

Combine (S)-4-benzyl-3-(4-fluorophenyl)acetyl-2-oxazolidinone (14.28 g, 45.6 mmol) and tetrahydrofuran (150 mL). Cool in a dry-ice/acetone bath. Add dropwise a solution of sodium bis(trimethylsilyl)amide (50 mL, 1.0 M in tetrahydrofuran, 50 mmol). After 25 minutes, add allyl iodide (13 mL, 142.2 mmol) and then replace the bath with a dry-ice/carbon tetrachloride bath. After 1 hour, quench the reaction by the addition of a saturated aqueous ammonium chloride solution, extract with diethyl ether, and separate the layers. Dry the organic layer over Na2SO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting with 1/6 ethyl acetate/hexane. Combine the product containing fractions, evaporate, and recrytallize from chloroform/hexane to give (S)-4-benzyl-3-(2-(4-fluorophenyl)pent-4-enoyl)-2-oxazolidinone: mp; 103-104° C. Rf=0.57 (silica gel, 20% ethyl acetate/hexane).

Provenance & Evidence