The development of a novel synthesis of acetophenone benzopyran is reported. A acetophenone benzopyran derivative was prepared from 1-(2,4-dihydroxyphenyl)ethanone (3) through O-prenylation and Lewis acids catalyzed intermolecular cyclization reaction. The structure of product 1-(3,4-dihydro-4,4-dimethyl-7-hydroxy-2H-1- benzopyran -6-yl)- ethanone (1) was characterized by UV, IR, 1H-NMR, 13C-NMR and elemental analysis.