Hexachloroethane → (2S,4R)-4-tert-butoxy-2-oxazol-2-yl-pyrrolidine-1-carboxylic acid benzyl ester

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of (2S,4R)-4-tert-butoxy-2-(2-oxo-ethylcarbamoyl)-pyrrolidine-1-carboxylic acid benzyl ester (4.5 g, 12.43 mmol) and hexachloroethane (5.88 g, 24.86 mmol) in dichloromethane (30 mL) was added triphenyl phosphine (6.52 g, 24.86 mmol) The mixture was stirred at 0° C. for 15 min, triethylamine (2.5 g, 24.86 mmol) was then added and the mixture was stirred at room temp. for 14 h. The reaction mixture was then extracted with dichloromethane and washed with water and brine. The organic layer was dried over anhydrous sodium sulfate and concentrated. The residue was purified by column chromatography (using 15% EtOAc in hexane as eluent) to give (2S,4R)-4-tert-butoxy-2-oxazol-2-yl-pyrrolidine-1-carboxylic acid benzyl ester (2 g, 46.6% yield) as a yellow liquid. MS calcd. for C19H25N2O4 [(M+H)+] 345.0, obsd. 345.2.

Provenance & Evidence