n-Butyl lithium (1.82 mL; 2.66 M solution in hexane) was added dropwise to a solution of diisopropylamine (0.735 mL) in THF (6 mL) at 0° C. The reaction solution was stirred at 0° C. for 20 minutes and then cooled to −78° C. Benzyl (3,4,5-trifluorophenyl)acetate (1.13 g) in THF (18 mL) was added dropwise to the reaction solution, and the reaction solution was stirred at −78° C. for 15 minutes. Thereafter, 3-(tert-butyldiphenylsiloxy)propanol (CAS No. 112897-03-7, 1.26 g) in THF (6 mL) was added dropwise to the reaction solution, and the reaction solution was stirred at −78° C. for 30 minutes. A saturated ammonium chloride solution was added to the reaction solution, and the reaction solution was returned to room temperature. Ethyl acetate was added and the organic layer was separated. The resulting organic layer was washed with brine, dried over anhydrous magnesium sulfate and then concentrated under reduced pressure. The residue was purified by silica gel column chromatography (elution solvent: heptane-ethyl acetate system) to obtain 840 mg of benzyl (2S*,3R*)-5-(tert-butyldiphenylsilanyloxy)-3-hydroxy-2-(3,4,5-trifluorophenyl)pentanoate and 765 mg of benzyl (2S*,3S*)-5-(tert-butyldiphenylsilanyloxy)-3-hydroxy-2-(3,4,5-trifluorophenyl)pentanoate.
