tetrasaccharide building blocks (1a/1b) for solid-phasesynthesis of glycopeptide were synthesized via stereoselective glycosylation of the disaccharyl Ser/Thr (3a/3b) with a glycosyl fluoride (2) carrying the 2-trichloroacetamido group that was readily converted into a 2-acetamido group by reduction. A segment of glycoprotein leukosialin (215–224) was synthesized by the solid-phase protocol, the building block (1b)