To a reaction vessel under a nitrogen atmosphere, 3.7 g of ethyl 2-fluoro-3-hydroxy-3-(4′-propyl-[1,1′-bi(cyclohexane)]-4-yl)propan oate (e-3), 6.5 g of DBU, 6.5 ml of carbon disulfide and 40 ml of DMF were added, and the resultant mixture was stirred at 25° C. for 1.5 hours. Subsequently, 15.3 g of methyl iodide was added to a reaction mixture, and the resultant mixture was stirred at 25° C. for 1.5 hours. Then, 100 ml of water and 100 ml of ethyl acetate were added to separate the mixture into an organic layer and an aqueous layer, and an extraction operation was performed. The resultant organic layer was isolated, and washed with water, an aqueous solution of sodium thiosulfate, and water, and then the resultant solution was dried over anhydrous magnesium sulfate. The resultant solution was concentrated under reduced pressure, the resultant residue was purified by a preparative isolation operation by means of column chromatography using a mixed solvent of heptane and ethyl acetate (heptane:ethyl acetate=9:1 in a volume ratio) as an eluent and silica gel as a filler, the resultant product was dried, and thus 2.2 g of ethyl 2-fluoro-3-(((methylthio)carbonothioyl)oxy)-3-(4′-propyl-[1,1′-bi(cyclohexane)]-4-yl)propanoate (e-4) was obtained. A yield based on compound (e-1) was 60.2%.
