Lithium aluminum hydride (64.0 mg) was suspended in THF (5.0 ml) and the whole was cooled to 0° C. A THF solution (5.0 ml) containing the compound (155 mg) obtained in Example 29-5 was dropped therein and the whole was stirred at 0° C. for 1 hour. After completion of the reaction, sodium sulfate decahydrate was added thereto until bubbling was stopped, and a 1 mol/l sodium hydroxide aqueous solution was then added thereto until a white precipitate was generated. A solid was separated by filtration and the solvent in the filtrate was then distillated off under reduced pressure, and the residue was dried under vacuum, thereby obtaining the subject compound (93.5 mg) as a yellow oily substance.
