Preparation method of oseltamivir

The invention provides a preparation method of oseltamivir, the method does not need to use noble metal to catalyze and remove a protecting group on nitrogen, the reaction condition is mild, the operation is simple and convenient, the steps are few, the cost is low, the yield is high, (1aR, 5aR, 5R)-1-(2-methylpropyl-2-yl)-5-(1-ethylpropoxy)-1a, 2, 5, 5a-tetrahydrobenzo [1, 2] aziridine-3-ethyl formate is used as an initial raw material, and the preparation method is simple and convenient to operate and high in yield. The preparation method comprises the following steps: carrying out ring opening and N-acetylation reactions, and finally removing tert-butyl and p-methoxybenzyl protecting groups to prepare oseltamivir. 本发明提供一种奥司他韦的制备方法，该法不需要使用贵金属催化脱除氮上保护基，反应条件温和、操作简便、步骤少、成本低、收率高，该法以(1aR，5aR，5R)-1-(2-甲基丙-2-基)-5-(1-乙基丙氧基)-1a,2,5,5a-四氢苯并[1,2]氮杂环丙烷-3-甲酸乙酯为起始原料，经历开环、N-乙酰化反应，最后脱除叔丁基和对甲氧基苄基保护基，制得奥司他韦。