Abstract: In the presence of cuprous iodide and molecular sieves, piperonal and maleates were transformed to dilactone precursor of sesamin with the direct use of samarium metal. The reaction was completed by double addition forming, and the reaction process was efficient and simple. The synthetic method was simple and novel, and the raw materials were easy to obtain. The reaction was carried out in an anhydrous system under dry air at room temperature. The influencing factors on the reaction were investigated. The sesamin precursor was thus afforded with 78% yield under the reaction conditions of optimization. On this basis, the reaction effects of other maleates such as diethyl maleate, dibutyl maleate and dimethyl fumarate were further studied and compared, the expected experimental results were obtained, and the reaction mechanism was discussed.

Key words: sesamin precursor, maleates, piperonal, samarium metal, cuprous iodide