To a solution of 1-[2-(4,5-diphenyloxazol-2-yl)-2-hydroxy-1-(2-hydroxyethyl)ethyl]-5-tert-butyldiphenylsilyloxy-3,4-dihydronaphthalene (1.5 g) in tetrahydrofuran (30 ml) were added triphenylphosphine (1.8 g) and diethyl azodiformate (1.2 ml) at room temperature. After being stirred for 12 hours at the same temperature, the mixture was poured into the mixture of ethyl acetate and water. The organic layer was washed with water and brine, dried over MgSO4, and evaporated in vacuo. The residue was purified by chromatography on silica gel to afford 1-[2-(4,5-diphenyloxazol-2-yl)tetrahydrofuran-3-yl]-5-tert-butyldiphenylsilyloxy-3,4-dihydronaphthalene (1.0 g).
