Abstract
In the introduction section we mentioned the influenza virus which has become a serious threat for humans all over the world, especially the avian influenza virus (H5N1). Scientists discovered that the first step of infection pathway is initiated through the binding between the viral envelope protein hemagglutinin and the trisaccharide on the cell surface. After invasion into the host cell, a series of bio-functions was expressed subsequently, including the replication of virus and the death of the host cell. Scientists are devoted to the pathology studies and trying to find more efficient drugs.In the second and the third sections, we discussed about the protections and glycosylations of the three monosaccharides which belongs to the trisaccharide mentioned before. In the fourth section, we summarized the one-pot glycosylation strategy.And the specific aim of this thesis are the synthesis of different kinds of monosaccharide building blocks via “one-pot protection strategy” and the synthesis of fully protected trisaccharide 42 using “one-pot glycosylation strategy.” After deprotection and further functional groups transformation, we could get the trisaccharides 38、39、40 and 41. Biological functions can be further studied. And we hope the results can be helpful for the drug design.