Preparation method of ribonucleoside

The invention provides a method for preparing ribonucleoside of a formula I, which comprises the following steps: forming a reaction mixture containing a deprotonation reagent, a coupling agent, a silylation reagent, a compound of a formula II and a compound of a formula III under conditions suitable for preparing the formula I, wherein a hydroxyl protecting group PG is an independent hydroxyl protecting group. According to the technical scheme provided by the invention, the defects of long reaction steps, low reaction yield, high preparation cost, complex post-treatment process and unsuitability for industrial large-scale preparation in the existing preparation method of the formula (I) are overcome, and a preparation method for directly synthesizing the formula (I) from the formula (II) in one step is provided. The method has few steps, high yield, simple and convenient operation and low cost, and the method is suitable for industrial large-scale production. 本发明提供一种制备核糖核苷式I的方法，包括以下步骤：在适于制备式I的条件下形成含有去质子化试剂、偶