Synthesis of a library of allyl alpha-L-arabinofuranosyl-alpha- or beta-D-xylopyranosides; route to higher oligomers.
Six isomeric disaccharides allyl 2,3,5-tri-O-benzoyl-alpha-l-arabinofuranosyl-alpha-d-xylopyranosides and beta-d-xylopyranosides were synthetized by the stereoselective glycosylation of pure allyl alpha- or beta-d-xylopyranosides with 1-O-acetyl-2,3,5-tri-O-benzoyl-l-arabinofuranose as donor, catalyzed with BF(3).Et(2)O in DCM. Regio- and stereoselective glycosylation with excess of donor furnished almost exclusively the trisaccharides allyl 2,3-di-O-(2,3,5-tri-O-benzoyl-alpha-l-arabinofuranosyl)-alpha- or beta-d-xylopyranosides. Extension of the reaction to the triol beta-d-xylopyranosyl-(1-->4)-1,2,3-tri-O-acetyl-alpha-d-xylopyranose, obtained from the 4-hydroxyl penta-O-acetyl-alpha-xylobiose, gave in the same manner the tetrasaccharide [2,3-di-O-(2,3,5-tri-O-benzoyl-alpha-l-arabinofuranosyl)-beta-d-xylopyranosyl]-(1-->4)-1,2,3-tri-O-acetyl-alpha-d-xylopyranose. The protocol described herein should offer the possibility to produce branched oligosaccharides with a 2,3-di-O-(alpha-l-Ara(f))-beta-d-Xyl(p) block unit at the terminal non-reducing end.
Utille
Jean-Pierre
JP
Centre de Recherches sur les Macromolécules Végétales (CERMAV-CNRS), BP53, 38041 Grenoble cedex 9, France. jean-pierre.utille@cermav.cnrs.fr
Jeacomine
Isabelle
I
D000498:Allyl Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D001089:Arabinose; D002236:Carbohydrate Conformation; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000737:chemistry; D002621:Chemistry / Q000379:methods*; D002845:Chromatography / Q000379:methods; D004187:Disaccharides / Q000138:chemical synthesis* / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008956:Models, Chemical; D008969:Molecular Sequence Data; D014994:Xylose
D000498:Allyl Compounds; D002241:Carbohydrates; D004187:Disaccharides; D014994:Xylose; D001089:Arabinose