6-Azido-Galactosyl Imidate as a Building Block for Preparation of 1-(4-Aminobutyl)-, Di-, Tri- and Tetra-Saccharides

6-azidogalactosyl imidate has been used as a donor to generate 1-(4-aminobutyl)-6-aminogalactose, 6-aminothiotolyl- glycosides of disaccharide, trisaccharide and tetrasaccharide that incorporates 6-azido group and 1-(4-tolyl)thio group. Trisaccharide and tetrasaccharide were obtained from lactosyl-based acceptor. The anomeric 1-(4-tolyl)thio group could be used to conjugate with sphingosine analogs to provide the alpha-Gal Sph analogs for library extension from the azido group.