Trisaccharides related to the core chain of human blood group determinants were synthesized by way of the phthalimido-chloride method; namely, β-D-Galp-(1 → 3)-β-D-GlcNAcp-(1 → 6)-D-Galp (3), β-D-Galp-(1 → 3)-β-D-GlcNAcp-(1 → 3)-D-Galp (5), β-D-Galp-(1 → 4)-β-D-GlcNAcp-(1 → 6)-D-Galp (4), and β-D-Galp-(1 → 4)-β-D-GlcNAcp-(1 → 3)-D-Galp (6). The syntheses of the 8-methoxy-carbonyloctyl β-glycosides of these trisaccharides are also reported.