title: 5-Ethynyl-2'-deoxycytidine: a DNA building block with a 'clickable' side chain.
abstract: The title compound [systematic name: 4-amino-1-(2-deoxy-β-D-erythro-pentofuranosyl)-5-ethynylpyrimidin-2(1H)-one], C(11)H(13)N(3)O(4), shows two conformations in the crystalline state. The N-glycosylic bonds of both conformers adopt similar conformations, with χ = -149.2 (1)° for conformer (I-1) and -151.4 (1)° for conformer (I-2), both in the anti range. The sugar residue of (I-1) shows a C2'-endo envelope conformation ((2)E, S-type), with P = 164.7 (1)° and τ(m) = 36.9 (1)°, while (I-2) shows a major C3'-exo sugar pucker (C3'-exo-C2'-endo, (3)T(2), S-type), with P = 189.2 (1)° and τ(m) = 33.3 (1)°. Both conformers participate in the formation of a layered three-dimensional crystal structure with a chain-like arrangement of the conformers. The ethynyl groups do not participate in hydrogen bonding, but are arranged in proximal positions.
authors.affiliation: Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie, Universität Osnabrück, Germany. frank.seela@uni-osnabrueck.de
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
authors.forename: Hui
authors.initials: H
authors.lastname: Mei
authors.forename: Hai
authors.initials: H
authors.lastname: Xiong
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
mesh_terms: D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry*; D003841:Deoxycytidine / Q000031:analogs & derivatives* / Q000737:chemistry; D006860:Hydrogen Bonding; D015394:Molecular Structure
chemical_list: C577017:4-amino-1-(2-deoxy-beta-D-erythro-pentofuranosyl)-5-ethynylpyrimidin-2(1H)-one; D003841:Deoxycytidine; D004247:DNA