| This thesis describes the syntheses of tumor associated carbohydrates: KH-1 antigen and N3 antigens. KH-1 nonasaccharide antigen, which is composed of a linear combination of a Lewis Y tetrasaccharide and a Lewis X trisaccharide, is found overexpressed on the surface of numerous tumor cells including colon cancer cells. On the other hand, N3 antigens, the two octasaccharide structural isomers that display prominent blood groups trisaccharides Lewis X and Lewis A, are thought to be related to gastrointestinal cancer. The convergent and concise syntheses of these complex carbohydrate antigens have been achieved by fully taking advantages of glycals as easily manipulable building blocks. In all cases, late stage multi-fucosylation reactions were carried out to maximize the convergency of the syntheses. Immunological evaluations for these synthetic antigens are in progress. |
