Dimethyl Sulfoxide → ethyl 3-{[(2R)-2-(4,5-diphenyloxazol-2-yl)-4-oxopyrrolidin-1-yl]methyl}phenoxyacetate

Participants

Reaction Steps

To a solution of oxalyl chloride (0.050 mL) in CH2Cl2 (10 mL) was added a solution of DMSO (0.061 mL) in CH2Cl2 (0.5 mL) keeping the temperature below −55° C., and stirred for 30 minutes. To the mixture was added a solution of ethyl 3-{[(2R, 4R)-2-(4,5-diphenyloxazol-2-yl)-4-hydroxypyrrolidin-1-yl]methyl}phenoxyacetate (238 mg) in CH2Cl2 (3 mL) at the same temperature, then stirred for 1 hour. To the reaction mixture was added triethylamine (0.27 mL), and warmed to room temperature over 30 minutes. After stirring at the same temperature for 30 minutes, the mixture was diluted with EtOAc, washed with water, saturated sodium hydrogen carbonate, water and brine, dried (MgSO4), evaporated. The residue was purified by silica gel column chromatography (hexane-EtOAc 2:1) to give ethyl 3-{[(2R)-2-(4,5-diphenyloxazol-2-yl)-4-oxopyrrolidin-1-yl]methyl}phenoxyacetate (191.8 mg).

Provenance & Evidence