SYNTHETIC APPROACH TOWARDS SULFATED CHONDROITIN DISACCHARIDES, TRISACCHARIDES AND TETRASACCHARIDES CORRESPONDING TO THE REPEATING UNIT

Chondroitin di-, tri- and tetrasaccharides, as well as their 4-, 6-mon o- and 4,6-disulfates as their 4-methoxyphenyl glycosides, were system atically synthesized. Target disaccharides having beta GalNAc (1-->4)- beta GlcA sequences were obtained starting from the corresponding pivo tal chondroitin disaccharide precursor. A trisaccharide intermediate, which was synthesized by coupling of glucuronate imidate with a known disaccharide acceptor, was transformed into the sulfated and non-sulfa ted chondroitin trisaccharides. Chondroitin tetrasaccharide and the co rresponding 4-disulfate, 6-disulfate as well as 4,6-tetrasulfate were also obtained based on the strategy developed above starting from the reported tetrasaccharide having [beta GalN(3)-(1-->4)-beta GlcA(2)] se quence. (C) 1998 Elsevier Science Ltd.