Synthesis of oligocaccharides Galβ1-3GlcNAcβ-sp, GlcNAcβ1-3Galβ1-3GlcNAcβ-sp, Galβ1-3GlcNAcβ1-3Galβ1-3GlcNAcβ-sp, Galβ1-3GlcNAcβ1-3Galβ1-4GlcNAcβ-sp, Galβ1-3GlcNAcβ1-6Galβ1-4GlcNAcβ-sp (sp = O(CH2)3NH2 or O(CH2)2NH2) was carried out using glycosylation by N-Troc-protected derivatives of glycosamine or disaccharide Galβ1-3GlcN.