Preparation method of omarigliptin intermediate

The invention discloses a novel synthesis method for preparing a chiral intermediate of omarigliptin. The method disclosed by the invention comprises the following steps: taking crotonyl chloride and (S)-4-benzyl-2-oxazolidone as starting raw materials and carrying out amidation, alder condensation, hydrolysis, Curtius rearrangement, Boc addition and ring opening to obtain the chiral intermediate (VI). The preparation method disclosed by the invention has the advantages of relatively short route, relatively low cost, easiness for obtaining the raw materials and relatively high yield so that the preparation method is suitable for industrial production. A formula is shown in the description. 本发明公开了种新的制备奥格列汀的手性中间体的合成方法，该方法包括以起始原料炔丙基脲和(S)-4-苄基-2-唑烷酮经酰胺化，alder缩合，水解，Curtius重排，上Boc、开环得到手性中间体(VI)。本发明的制备方法路线较短，成本较低，原料易得，产率较高，适于工业化生产。