A solution of the 5-[(1R,2S)-2-(benzyloxy)cyclopentyl]-1H-pyrazole (322 mg, 1.33 mmol) prepared in Example 148c, 3,4-dihydro-2H-pyran (0.728 mL, 7.98 mmol) and p-toluenesulfonic acid hydrate (50 mg, 0.266 mmol) in dichloromethane (5.0 mL) was stirred for 3 hours under reflux. After allowing to cool, the reaction solution was vacuum concentrated, and the residue was purified with silica gel chromatography (hexane/ethyl acetate=7:3) to yield the title compound (402 mg, 93%) in the form of a diastereomeric mixture as a colorless oil.
