The crystal structure of penta-O-acetyl-beta-D-galactopyranose was determined with Mo K(alpha) radiation at 150 K to R = 0.029. The space group is P2(1)2(1)2(1), and the unit cell dimensions are, a = 8.348, b = 9.021 and c = 25.418 A.
1,2,3,4,6-Penta-O-acetyl-beta-D-galactopyranose was transformed into phenyl 2,3,4,6-tetra-O-benzyl-1-thio-beta-D-galactopyranoside (5) and 4-methoxyphenyl 2,3,6-tri-O-benzoyl-beta-D-galactopyranoside (8) in 73% (two steps) and 58% (three steps) yield, respectively. Glycosylation of the acceptor 8 with donor 5 using N-iodosuccinimide-trimethylsilyl trifluoromethanesulfonate as promoter furnished the galabioside 9 (8.8 g)
Comparative X-ray diffraction analysis of 5,6,7,9-tetra-O-acetyl-4,8-anhydro-1,3-dideoxy-D-glycero-L-gluco-nonulose (1) and a structurally related analog, 1,2,3,4,6-penta-O-acetyl-beta-D-galactopyranose (2), are reported. Both crystals have one molecule in the unit cell and the pyranose rings in both exist in the 4C1 conformation.
Zeolite-catalyzed glycosylation of long-chain alcohols, using the inexpensive and readily available peracetylated beta-D-gluco- and galactopyranoses as glycosyl donors under solvent free conditions, has been explored for the first time. Among the various forms (H-, Na-, Fe- and Zn) of beta
Questions
Évaluations
★★★★★ Aucune valeur de notation
Filtres actifs
Notre équipe de scientifiques dispose d'une expérience dans tous les secteurs de la recherche, notamment en sciences de la vie, science des matériaux, synthèse chimique, chromatographie, analyse et dans de nombreux autres domaines..
