Ammonium Chloride → (S,E)-3-(pent-2-enoyl)-4-phenyloxazolidin-2-one

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Reaction Conditions

Reaction Steps

(S)-(+)-4-Phenyl-2-oxazolidinone (4.0 g, 24 mmol, Aldrich) was dissolved in dry THF (40 mL), and the solution was cooled to -50° C. and flushed with N2. Sodium hexamethyldisilazane (1.0M in THF, 25 mL, 25 mmol) was added slowly with stirring. The compound from step 7a (2.9 g, 24 mmol) was added slowly while maintaining the temperature at -50° C., and the mixture was stirred at this temperature for 1.5 hour. The mixture was allowed to warm to 0° C. and stirred for 1 hour. Saturated aqueous NH4Cl solution was added, the mixture was stirred for 10 minutes and the mixture was extracted with methylene chloride. The extract was dried over Na2SO4, filtered and the solvent was removed. The residue was chromatographed on silica gel, eluting with 2% methanol/methylene chloride, and the product was rechromatographed with 0.5% methanol/methylene chloride to give the title compound (1.69 g). MS m/z 246 (M+H)+, 263 (M+NH4)+.

Provenance & Evidence