In this diploma thesis, the linear trisaccharide Xyl(β1-4)Rha(α1-2)Fuc, an important domain of the immunostimulatory saponin QS-21 was prepared. The natural compound QS-21, isolated from the bark of Quillaja saponaria tree, is one of the strongest known adjuvants. Adjuvants are the key components of the vaccine that improve the immune response to the applied antigen. The linear trisaccharide will be synthesized from protected monosaccharide precursors. Two glycosylation methods will be compared: i) using allyl as protecting / activating groups, and ii) using glycosyl fluoride as a donor and silyl ether as an acceptor. The second method is more robust and is expected to give better results. Advantages of this method are quick and easy approach, the commercially available catalyst, the fact that strict conditions without moisture and oxygen are not required, and that the reaction is carried out at room temperature. The aim of this work is to prepare the target linear trisaccharide in the simplest possible synthetic way and in the best possible yield. The intermediates in the synthesis, as well as the final product, will be characterized by spectroscopic methods (IR, NMR).