title: Synthesis of a heptasaccharide hapten related to a biantennary glycan chain of human chorionic gonadotropin of a choriocarcinoma patient. A convergent approach.
abstract: Synthesis of the heptasaccharide hapten 8-methoxycarbonyloctyl O-beta-D-galactopyranosyl-(1----4)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----2)-O-[beta-D-galactopyranosyl-(1----4)-O-(2-acetam ido-2- deoxy-beta-D-glucopyranosyl)-(1----4)]-O-alpha-D-mannopyranosyl-(1----3) -O- [alpha-D-mannopyranosyl-(1----6)]-beta-D-mannopyranoside is described, by use of the known, protected glycosyl acceptor 8-ethoxy-carbonyloctyl O-(2,3,4,6-tetra-O-benzyl-alpha-D-mannopyranosyl)-(1----6)-2,4-di-O-benz yl-beta - D-mannopyranoside, and the key glycopentaosyl donors O-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-(1----4)-O-(2-acetami do-3,6- di-O-acetyl-2-deoxy-beta-D-glucopyranosyl)-(1----2)-O-[(2,3,4,6-tetra-O- acetyl-beta-D-galactopyranosyl)-(1----4)-O-(2-acetamido-3,6-di-O-acetyl- 2- deoxy-beta-D-glucopyranosyl)-(1----4)]-3,6-di-O-benzyl-alpha-D-mannopyra nosyl trichloroacetimidate (5) and the corresponding fluoride 7, which, in turn, were prepared in 5 steps from allyl 3,6-di-O-benzyl-alpha-D-mannopyranoside in 35 and 22% overall yields, respectively. In model experiments, the key glycosyl donors 5 and 7 were also treated with the simple glycosyl acceptor 8-ethoxycarbonyloctanol, to give 8-methoxycarbonyloctyl O-beta-D-galactopyranosyl-(1----4)-O-(2-acetamido-2-deoxy-beta-D- glucopyranosyl)-(1----2)-O-[beta-D-galactopyranosyl-(1----4)-O-(2-acetam ido-2- deoxy-beta-D-glucopyranosyl)-(1----4)]-alpha (and beta)-D-mannopyranoside.
mesh_terms: D002822:Choriocarcinoma / Q000652:urine; D006063:Chorionic Gonadotropin / Q000138:chemical synthesis* / Q000652:urine; D005260:Female; D006241:Haptens; D006801:Humans; D007202:Indicators and Reagents; D009682:Magnetic Resonance Spectroscopy; D009844:Oligosaccharides / Q000138:chemical synthesis*; D011134:Polysaccharides; D011247:Pregnancy; D014594:Uterine Neoplasms / Q000652:urine
chemical_list: D006063:Chorionic Gonadotropin; D006241:Haptens; D007202:Indicators and Reagents; D009844:Oligosaccharides; D011134:Polysaccharides