The glycopeptides 1 (Gly[O-beta-D-Xylp)-L-Ser-Gly-L-Glu) and 2 (Gly[O-[beta-D-GlcpA-(1-->3)-beta-D-Galp-(1-->3)-beta-D-Galp]-(1-- >4) -beta-D-Xylp)-L-Ser-Gly-L-Glu), carrying the core structure of serine-linked cell-surface proteoglycans were synthesized in a stereocontrolled manner. The carbohydrate key imidate xylosyl donors 3 and glycotetraosyl donors 4 and 5, as well as a tetrapeptide glycosyl acceptor 6, were coupled in the crucial glycosylation step. In these reactions, the application of either trimethylsilyl trifluoromethanesulfonate (TMSOTf) or borontrifluoride etherate (BF3-Et2O) as catalysts proved to be highly efficient. The serine linked glycopeptides 34, 36 and 37 thus obtained yielded target compounds 1 and 2 on complete deprotection.