(S)-4-Benzyl-2-oxazolidinone → (4S)-4-benzyl-3-(5-cyclohexylpentanoyl)-1,3-oxazolidin-2-one

Participants

Reaction Steps

A solution of n-butyllithium (100 ml, 250 mmol, 2.5M in hexanes) was added via a cannula to a solution of (4S)-4-benzyl-1,3-oxazolidin-2-one (44.30 g, 250 mmol) in anhydrous tetrahydrofuran (400 ml) at −78° C. The yellow solution was then stirred for 45 minutes. A solution of 5-cyclohexylpentanoyl chloride (55.5 g, 275 mmol) in tetrahydrofuran (100 ml) was then added over 1 hour. The mixture was stirred at −78° C. for 30 minutes then warmed to room temperature over 1 hour. The mixture was quenched with an aqueous solution of ammonium chloride (20% w/v, 400 ml) and extracted with ethyl acetate. The layers were separated and the organic layer was washed with brine, dried over anhydrous sodium sulphate and the solvent removed under reduced pressure. The solid was recrystallised from hexane (500 ml) to afford the title compound as a white solid (81.0 g).

Provenance & Evidence