synthesis and molecular structure of methyl 4-o-methyl-α-d-glucopyranuronate合成和分子结构的甲基4-o-methyl-α-d-glucopyranuronate.pdf

Molecules 2005, 10, 251–258 molecules ISSN 1420-3049 Synthesis and Molecular Structure of Methyl 4-O-methyl-α-D- glucopyranuronate Ján Hirsch 1, Vratislav Langer 2 and Miroslav Koóš 1,* 1 Institute of Chemistry, Slovak Academy of Sciences, Dúbravská cesta 9, SK-845 38 Bratislava, Slovakia, Tel. +421 2 Fax +421 2 2 Department of Environmental Inorganic Chemistry, Chalmers University of Technology, SE-41296 Göteborg, Sweden. * Author to whom correspondence should be addressed; e-mail: chemmiro@savba.sk Received: 17 August 2004; in revised form: 22 November 2004 / Accepted: 23 November 2004 / Published: 31 January 2005 Abstract: A method for the preparation of methyl 4-O-methyl-α-D-glucopyranuronate and its single crystal X-ray structure determination are reported. The molecule adopts an almost ideal 4 C (OC ) conformation. 1 3 Keywords: Glucuronate, X-ray crystal structure, conformation. Introduction (4-O-Methylglucurono)xylans are important constituents of cell-wall polysaccharides of woods and other plants. These biopolymers are composed mainly of (1→4)-β-linked D-xylopyranoses, some of which are randomly branched at position O-2 with 4-O-methyl-α-D-glucopyranosyluronic acid. In this respect, methyl (benzyl 2,3-di-O-benzyl-4-O-methyl-β-D-glucopyranosid)uronate (1) and methyl 4-O-methyl-α-D-glucopyranuronate (2) represent very useful compounds in the synthesis and structural studies of model aldobiouronic acids (needed in studies related to chemical processing of wood) that reflect these structural features [1–4]. Regarding the preparation of 2, there