Total synthesis of the carbohydrate-protein linkage region common to several mammalian proteoglycans.

A stereocontrolled synthesis of beta-D-GlcpA-(1--> 3)-beta-D-Galp-(1-->3)-beta-D-Galp-(1-->4)-beta-D-Xylp-(1 --> O)-L-Ser-Gly, the common glycopeptide sequence of the carbohydrate-protein linkage region of most mammalian proteoglycans, was achieved by use of O-[2-(trimethylsilyl)ethyl 2,3,4-tri-O-benzoyl-beta-D-glucopyranosyluronate] -(1-->3)-O-(2,4,6-tri-O-benzoyl-beta-D-galactopyranosyl)-(1-->3)-O-(2,4, 6-tri -O-benzoyl-beta-D-galactopyranosyl)-(1-->4)-2,3-di-O-benzoyl-alpha, beta-D- xylopyranosyl trichloroacetimidate as the key intermediate. Condensation of this glycosyl donor with suitably protected L-seryl-glycine dipeptide segments, and peptide chain elongation, allowed the construction in high yield of complex structures of this linkage region.