The total syntheses of two octasaccharide antigens isolated from human milk, 1 and 2, and their corresponding allyl glycosides, 3 and 4, have been achieved by utilizing the glycal method, Convergent assembly of the core hexasaccharides and concurrent introduction of two alpha -L-fucosyl moieties at the late stage of the syntheses provided these complex:carbohydrates in a concise manner. With synthetic material obtained, biological evaluations of these antigens as potential gastrointestinal cancer immunotherapeutic agents have been initiated.