1,1'-Carbonyldiimidazole → (S)-(+)-5,5-Dimethyl-4-phenyl-2-oxazolidinone

Participants

Reaction Conditions

Reaction Steps

A solution of C2 (38.8 g, 235 mmol) in dichloromethane (1000 mL) was treated with carbonyldiimidazole (45.6 g, 281 mmol) and heated at reflux for 2 hours. The reaction mixture was cooled to 25° C., quenched with 1 N hydrochloric acid (560 mL), and extracted with dichloromethane (3×). The combined organic extracts were dried over sodium sulfate and concentrated, and the resultant residue was purified by trituration with 4:1 hexanes:ethyl acetate, followed by chromatography on silica gel (gradient: 9:1 hexanes:ethyl acetate to 1:1 hexanes:ethyl acetate) to provide C3 as a white solid. Yield: 24.7 g, 55%. MS (APCI) m/z 192.2 (M+1). 1H NMR (400 MHz, CDCl3) δ 0.91 (3H, s), 1.58 (3H, s), 4.62 (1H, s), 5.53-5.60 (1H, br s), 7.20-7.39 (5H, m).

Provenance & Evidence