title: Synthesis of the two monomethyl esters of the disaccharide 4-O-alpha-D-galacturonosyl-D-galacturonic acid and of precursors for the preparation of higher oligomers methyl uronated in definite sequences.
abstract: Methyl (alpha-D-galactopyranosyluronic acid)-(1-->4)-D-galactopyranuronate and methyl alpha-D-galactopyranosyl-uronate-(1-->4)-D-galactopyranuronic acid have been synthesized by coupling methyl (benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate (3) or benzyl (benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate (4) with benzyl (phenyl 2,3,4-tri-O-benzyl-1-thio-beta-D-galactopyranosid)uronate and methyl (phenyl 2,3,4-tri-O-benzyl-1-thio-beta-D-galactopyranosid)uronate, respectively, using N-iodosuccinimide and trifluoromethanesulphonic acid as promoters, followed by removal of the benzyl groups. The 4'-OH unprotected dimers benzyl (methyl 2,3-di-O-benzyl-alpha-D-galactopyranosyluronate)-(1-->4)-(benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate and methyl (benzyl 2,3-di-O-benzyl-alpha-D-galactopyranosyluronate)-(1-->4)-(benzyl 2,3-di-O-benzyl-beta-D-galactopyranosid)uronate were prepared from methyl (phenyl 2,3-di-O-benzyl-1-thio-4-O-trimethylsilyl-beta-D-galactopyranosid) uronate and benzyl (phenyl 2,3-di-O-benzyl-1-thio-4-O-trimethylsilyl-beta-D-galactopyranosid) uronate and acceptors 4 or 3, respectively. These compounds have been designed to serve as precursors for the preparation of higher-membered D-galacturonic acid oligomers methyl esterified in definite positions.
authors.affiliation: Laboratoire de Chimie Organique, EA 1844, Institut National des Sciences Appliquées, Villeurbanne, France.
authors.forename: D
authors.initials: D
authors.lastname: Magaud
authors.forename: C
authors.initials: C
authors.lastname: Grandjean
authors.forename: A
authors.initials: A
authors.lastname: Doutheau
authors.forename: D
authors.initials: D
authors.lastname: Anker
authors.forename: V
authors.initials: V
authors.lastname: Shevchik
authors.forename: N
authors.initials: N
authors.lastname: Cotte-Pattat
authors.forename: J
authors.initials: J
authors.lastname: Robert-Baudouy
mesh_terms: D004952:Esters / Q000138:chemical synthesis*; D006031:Glycosylation; D006603:Hexuronic Acids / Q000138:chemical synthesis*; D008956:Models, Chemical
chemical_list: D004952:Esters; D006603:Hexuronic Acids; C007819:galacturonic acid