Abstract 2-Propenoic acid when reacted with 1-acetoxy-2-phenoxyethane in polyphosphoric acid at room temperature gives intermolecular acylalkylated produkt I. Probably owing to a rapid subsequent reaction the acylated intermediary product could not be detected. Therefore alkylation of a model compound, 1-acetoxy-2-phenoxyethane, with derivatives of 1-phenyl-2-propen-1-one was investigated, which led to compound I-IV.