title: Crystal and molecular structure of methyl L-glycero-α-D-manno-heptopyranoside, and synthesis of 1→7 linked L-glycero-D-manno-heptobiose and its methyl α-glycoside.
abstract: Methyl l-glycero-α-d-manno-heptopyranoside was synthesized in good yield by a Fischer-type glycosylation of the heptopyranose with methanol in the presence of cation-exchange resin under reflux and microwave conditions, respectively. The compound crystallized from 2-propanol in an orthorhombic lattice of space group P2(1)2(1)2 showing a comparatively porous structure with a 2-dimensional O-H⋯O hydrogen bond network. As model compounds for the side chain domains of the inner core structure of bacterial lipopolysaccharide, l-glycero-α-d-manno-heptopyranosyl-(1→7)-l-glycero-d-manno-heptopyranose and the corresponding disaccharide methyl α-glycoside were prepared. The former compound was generated via glycosylation of a benzyl 5,6-dideoxy-hept-5-enofuranoside intermediate followed by catalytic osmylation and deprotection. The latter disaccharide was efficiently synthesized in good yield by a straightforward coupling of an acetylated N-phenyltrifluoroacetimidate heptopyranosyl donor to a methyl 2,3,4,6-tetra-O-acetyl heptopyranoside acceptor derivative followed by Zemplén deacetylation.
authors: Department of Chemistry, University of Natural Resources and Life Sciences, Vienna, Austria.
authors: Daniel
authors: D
authors: Artner
authors: Christian
authors: C
authors: Stanetty
authors: Kurt
authors: K
authors: Mereiter
authors: Alla
authors: A
authors: Zamyatina
authors: Paul
authors: P
authors: Kosma
mesh_terms: D018360:Crystallography, X-Ray; D006027:Glycosides / Q000737:chemistry*; D006539:Heptoses / Q000737:chemistry*; D008070:Lipopolysaccharides / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure
chemical_list: D006027:Glycosides; D006539:Heptoses; D008070:Lipopolysaccharides; C062615:glycero-alpha-manno-heptopyranose