5.0 g (17.3 mM) of 8,8,9,9,10,10,10-heptafluoro-3,6-dioxadecanol and 4.8 ml of pyridine were stirred under cooling on an ice bath. To the mixture, 4.0 g (20.8 mM) of p-toluenesulfonyl chloride was added, followed by stirring for 3 hours. The reaction mixture was poured into water and acidified by hydrochloric acid, followed by extraction with ethylacetate, washing with water, drying with anhydrous sodium sulfate and distilling-off of the solvent to obtain a residue. The residue was purified by silica gel column chromatography (eluent: toluene/ethyl acetate=10/1) to obtain 7.92 g of 8,8,9,9,10,10,10-heptafluoro-3,6-dioxadecyl p-toluenesulfonate (Yield: 99.8%).
