title: Schiff bases or glycosylamines: crystal and molecular structures of four derivatives of D-mannose.
abstract: Crystal and molecular structures of four derivatives of D-mannose are described. Each could exist as either an open-chain Schiff base or as a glycosylamine in the solid state. The derivative formed upon reaction of D-mannose with hydroxylamine is an open-chain oxime, but those formed upon reaction with semicarbazide, aniline, and p-chloroaniline are glycosylamines. The oxime, which crystallizes as the syn-(E) isomer, has a fully extended carbon chain. The glycosylamines are all beta-pyranoses. The packing arrangement of the oxime involves 'head-to-tail' hydrogen bonding. The semicarbazide derivative, which crystallizes as a dihydrate, features a hydrogen-bonded intramolecular bridge formed by the two water molecules and linking O-6 to the carbonyl oxygen atom. The packing arrangements of the aniline and p-chloroaniline derivatives differ from each other but are nevertheless closely related by similar hydrogen-bonding interactions.
authors.affiliation: Department of Chemistry, University of St. Thomas, St. Paul, MN 55105, USA. whojala@stthomas.edu
authors.forename: W H
authors.initials: WH
authors.lastname: Ojala
authors.forename: J M
authors.initials: JM
authors.lastname: Ostman
authors.forename: C R
authors.initials: CR
authors.lastname: Ojala
mesh_terms: D000588:Amines / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008358:Mannose / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D010091:Oximes / Q000737:chemistry; D012545:Schiff Bases / Q000737:chemistry*
chemical_list: D000588:Amines; D010091:Oximes; D012545:Schiff Bases; D008358:Mannose