Allyl bromide → 4-Benzyl-3-(2-cyclohexyl-pent-4-enoyl)-oxazolidin-2-one

Participants

Reaction Steps

To a solution of 4-benzyl-3-(2-cyclohexyl-acetyl)-oxazolidin-2-one (16.0 g, 53 mmol) in anhydrous tetrahydrofuran at −78° C. was added a 1.0 M solution of sodium bis(trimethylsilyl)-amide (79.0 mL, 79 mmol), and the reaction mixture was stirred for 1 h. To the reaction mixture was then added allyl bromide (18.4 mL, 213 mmol), and the temperature was raised to −45° C. The reaction mixture was stirred at this temperature for 3 h. The reaction was quenched with aqueous saturated NH4Cl solution, and the resulting mixture was warmed to room temperature. The reaction mixture was extracted with ethyl acetate, and the combined extracts were washed with brine. The organic layers were dried (MgSO4) and concentrated in vacuo to yield a residue that was purified by silica gel column chromatography (5:1 hexanes:ethyl acetate) to yield (4-benzyl-3-(2-cyclohexyl-pent-4-enoyl)-oxazolidin-2-one) as a thick liquid that became a solid upon storage.

Provenance & Evidence