After an aqueous solution (22 ml) of sodium chlorite (2.6 g, 29 mmol) and sodium dihydrogenphosphate monohydrate (2.6 g, 19 mmol) was added dropwise to a solution of allyl (4′-{[3-(allyloxy)-2-formyl-4-(trifluoromethyl)benzyl]oxy}-3-fluoro-1,1′-biphenyl-4-yl)acetate (2.52 g, 4.8 mmol) obtained in Example (11-5) in a mixture of tert-butyl alcohol (51 ml), 1,4-dioxane (17 ml) and 2-methyl-2-butene (17 ml), the mixture was stirred at room temperature for 90 minutes. After a 5% aqueous sodium thiosulfate solution was added to the reaction mixture, the mixture was poured into 1N hydrochloric acid and the mixture was extracted with ethyl acetate (twice). The organic layer was successively washed with water and a saturated aqueous NaCl solution and dried with anhydrous sodium sulfate. The solvent was removed under reduced pressure to give a residue. Methylene chloride (50 ml), 2-methyl-1-propene (150 ml) and sulfuric acid (1 ml) were successively added to the obtained residue and the mixture was stirred at room temperature overnight. After the reaction mixture was poured into a 5% aqueous sodium hydrogencarbonate solution and the mixture was extracted with ethyl acetate (twice), the organic layer was successively washed with water and a saturated aqueous NaCl solution and dried with anhydrous sodium sulfate. The residue obtained by removing the solvent under reduced pressure was purified by silica gel column chromatography (eluting solvent: n-hexane/ethyl acetate=10/1-3/1) to give tert-butyl 2-(allyloxy)-6-{[(4′-{[(allyloxy)carbonyl]methyl}-3′-fluoro-1,1′-biphenyl-4-yl}oxy]methyl)-3-(trifluoromethyl)benzoate as a colorless powder (2.38 g, yield: 83%).
