Water → HCID 59389336、化合物

A 1 mol/L tetrabutylammonium fluoride-tetrahydrofuran solution (35.1 mL) was added dropwise to a solution of the compound of Example 325 (8.76 g) in tetrahydrofuran (120 mL) at 0° C. The mixture was stirred at 0° C. for 30 min. Subsequently, water was added and the mixture was extracted with ethyl acetate (300 mL). The organic layer was washed sequentially with water and saturated brine and dried over anhydrous sodium sulfate. The extract was concentrated and purified by silica gel column chromatography (hexane:ethyl acetate=3:1) to afford the title compound as a colorless powder (6.00 g).