To a 100 mL round-bottomed flask equipped with condenser and N2 inlet were added 241 mg (0.983 mmol) 3-hydroxy-1-(4-trifluoromethyl-phenyl)-pyrrolidin-2-one, 15 mL dry tetrahydrofuran, 645 mg (2.45 mmol) triphenylphosphine, and 328 mg (1.18 mmol) N-(2-hydroxyphenyl)-4-t-butoxycarbonyl-piperazine. A solution of 398 mg (1.97 mmol) disopropyl azodicarboxylate in 10 mL dry tetrahydrofuran was added dropwise over 5 minutes, and the reaction stirred at room temperature overnight. The reaction was quenched with aqueous sodium bicarbonate solution, separated, and the aqueous layer extracted three times with ethyl acetate. The combined organic layers were dried over magnesium sulfate and evaporated. The residue was chromatographed on silica using hexane/ethyl acetate as eluant to afford 320 mg (64%) of an oil.
