Cyclopentanone (0.017 mL, 0.186 mmol) and a 0.3 mol Zn[B(CN)H3]2 methanol solution (0.4 mL, 0.12 mmol, prepared from ZnCl2 and NaB(CN)H3) were added to a methanol solution (1 mL) of 4-benzyloxy-1-{4-[(3S)-3-pyrrolidinyloxy]phenyl}-1H-pyridin-2-one (45 mg, 0.124 mmol) and sired at room temperature for an hour. Ethyl acetate was added to the reaction liquid, which was then washed with saturated aqueous sodium bicarbonate solution and saturated brine, and dried over anhydrous potassium carbonate. The solvent was concentrated under reduced pressure and the resulting residue was purified on silica gel chromatography (C-300; methanol:chloroform=1:10) to provide the title compound (28.2 mg, 53%).
