The compound (2.62 g) obtained in Example 121-5 was dissolved in anhydrous THF (100 ml) and added with lithium aluminum hydride (555 mg) under ice-cooling, followed by stirring for 30 minutes under a nitrogen atmosphere. After completion of the reaction, the solution was added with methanol and then added with an aqueous potassium sodium tartrate solution, followed by stirring overnight. The solution was extracted with chloroform and the extract was washed with saturate saline solution. Then, the organic layer was dried with anhydrous sodium sulfate. The solvent was distilled off, thereby obtaining the subject compound (2.64 g) as a white solid.
