Key intermediate of antiepileptic drug and preparation method of key intermediate

The invention discloses a key intermediate of an antiepileptic drug and a preparation method of the key intermediate. The method is used for synthesizing the key intermediate (R)-4-propyldihydrofuran-2(3H)-one of the antiepileptic drug, and has the following beneficial effects that a chiral preparation method is adopted, so that preparation of a chiral chromatographic column and resolution of a chiral resolving agent are avoided, and the total yield of the process is greatly improved. The structure of the intermediate 3 greatly improves the selectivity of asymmetric hydrogenation, and the ee value can reach 99% or above. A column-passing purification method is avoided, the operation process is simple, and the method is more suitable for industrial production. 本发明公开了一种抗癫痫药物的关键中间体及其制备方法，该方法用于合成抗癫痫药物的关键中间体（R）-4-丙基二氢呋喃-2（3H）-酮的方法，具有以下益处：采用手性制备的方法，避免了手性色谱柱制备、手性拆分剂拆分，大大提高了工艺总收率。中间体3的结构大大提高了不对称氢化的选择性，ee值可达到99%以上。避免了过柱的纯化方法，操作过程简单，更适宜工业化生产。