In 3 ml of anhydrous N,N-dimethylformamide was dissolved 220 mg of (4R)-4-phenylacetamido-3-isoxazolidinone. To the solution was added, under ice-cooling and stirring, 60 mg of sodium hydride (50% mineral oil), which was stirred for 10 minutes. Then the reaction solution was cooled to -10° C., to which was added under stirring 0.7 ml of anhydrous N,N-dimethylformamide solution dissolving 250 mg of the Compound (28) obtained in Example 28. The reaction solution was stirred at the same temperature for 45 minutes, followed by pouring into a mixture of ethyl acetate and water. The ethyl acetate layer was taken, washed with water and dried (Na2SO4). The solvent was evaporated off, and the residue was subjected to a silica gel column chromatography, followed by elution with hexane-ethyl acetate (2:1) to give 87 mg of the subject Compound (32) as colorless foamy substance.
