To 7-methoxy-1,1-dimethyl-3,4-dihydro-1H-naphthalen-2-one (Compound A2, 10 g), 2-bromo-1,3-dihydroxytetrahydropyranbenzene (Compound Z9, 20.98 g), sodium t-butoxide (5.88 g), palladium acetate (550 mg) and tri-t-butylphosphonium tetrafluoroborate (710 mg), toluene (40 mL) was added and the mixture was stirred and heated at 70° C. under nitrogen atmosphere for 6 hr. After cooling, the reaction mixture was added with methanol (38 mL) and trifluoroacetic acid (14.54 mL) at room temperature, and then stirred at room temperature overnight. To the resulting residues, methylene chloride and saturated dipotassium hydrogen phosphate were added and the organic layer was washed with saturated brine. Thereafter, the organic layer was dried over magnesium sulfate. The residues obtained after concentration under reduced pressure were purified by silica gel column chromatography (ethyl acetate/hexane) to obtain the title compound (5.53 g, 36%).
