[C:1]([OH:8])(=O)/[CH:2]=[CH:3]\[C:4]([OH:6])=[O:5].Br[C:10]1[C:19]2[C:14](=[CH:15][CH:16]=[CH:17][CH:18]=2)[CH:13]=[CH:12][CH:11]=1.O>O1CCCC1>[C:18]1([C:1](=[O:8])[CH:2]=[CH:3][C:4]([OH:6])=[O:5])[C:19]2[C:14](=[CH:13][CH:12]=[CH:11][CH:10]=2)[CH:15]=[CH:16][CH:17]=15.88 g(60 mmol) of dry maleic acid was dissolved in 100 ml of dry tetrahydrofuran and the mixture was cooled down to 78° C. 4.14 g(20 mmol) of 1-bromonaphthalene was dissolved in 100 ml of dry tetrahydrofuran and 13.8 ml of 1.6N n-butyllithium-hexane solution was added thereto at 78° C. This reaction solution was stirred for 5 minutes and then it was added to the dry maleic acid solution prepared in advance using cannula. The resulting mixture was stirred for 10 minutes, and water was added thereto to stop the reaction. The solvent was removed under reduced pressure, and the residue was acidified by 1N aqueous hydrochloric acid solution and extracted with ethyl acetate. The organic layer was washed with water and aqueous sodium chloride solution, dried over anhydrous magnesium sulfate, concentrated under reduced pressure and subjected to column chromatography(eluent: ethyl acetate/hexane=2/1, v/v) to give 1.35 g(6.0 mmol; Yield 30%) of the title compound.
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