title: 1,7-Dideaza-2'-deoxy-6-nitronebularine: a pyrrolo[2,3-b]pyridine nucleoside with an intramolecular hydrogen bond stabilizing the syn conformation.
abstract: The title compound [systematic name: 1-(2-deoxy-β-D-erythro-pentofuranosyl)-4-nitro-1H-pyrrolo[2,3-b]pyridine], C₁₂H₁₃N₃O₅, forms an intramolecular hydrogen bond between the pyridine N atom as acceptor and the 5'-hydroxy group of the sugar residue as donor. Consequently, the N-glycosylic bond exhibits a syn conformation, with a χ torsion angle of 61.6 (2)°, and the pentofuranosyl residue adopts a C2'-endo envelope conformation (²E, S-type), with P = 162.1 (1)° and τm = 36.2 (1)°. The orientation of the exocyclic C4'-C5' bond is +sc (gauche, gauche), with a torsion angle γ = 49.1 (2)°. The title nucleoside forms an ordered and stacked three-dimensional network. The pyrrole ring of one layer faces the pyridine ring of an adjacent layer. Additionally, intermolecular O-H∙∙∙O and C-H∙∙∙O hydrogen bonds stabilize the crystal structure.
authors.affiliation: Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany.
authors.forename: Haozhe
authors.initials: H
authors.lastname: Yang
authors.forename: Simone
authors.initials: S
authors.lastname: Budow
authors.forename: Henning
authors.initials: H
authors.lastname: Eickmeier
authors.forename: Hans
authors.initials: H
authors.lastname: Reuter
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
mesh_terms: D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009705:Nucleosides / Q000138:chemical synthesis / Q000737:chemistry*; D011725:Pyridines / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D009705:Nucleosides; D011725:Pyridines
keywords: crystal structure; disorder; nucleosides