Structures of 1-(2,3-dideoxy-erythro-<script type="math/tex">\alpha</script>-d-hexopyranosyl)thymine and the 1-(2,3-dideoxy-erythro-<script type="math/tex">\beta</script>-d-hexopyranosyl)thymine.dioxane complex

De Winter, H.L.; Blaton, N.M.; Peeters, O.M.; De Ranter, C.J.; Van Aerschot, A.; Herdewijn, P.

doi:10.1107/S0108270190010538

Title

Structures of 1-(2,3-dideoxy-erythro- $\alpha$ -d-hexopyranosyl)thymine and the 1-(2,3-dideoxy-erythro- $\beta$ -d-hexopyranosyl)thymine.dioxane complex

Author

De Winter, H.L.

Blaton, N.M.

Peeters, O.M.

De Ranter, C.J.

Van Aerschot, A.

Herdewijn, P.

Abstract

(1) 1-(2,3-Dideoxy-erythro-alpha-D-hexopyranosyl)thymine, C11H16N2O5, M(r) = 256.26, orthorhombic, P2(1)2(1)2(1), a = 4.871 (2), b = 13.182 (7), c = 18.678 (9) angstrom, V = 1199 (1) angstrom3, Z = 4, D(m) = 1.43, D(x) = 1.419 Mg m-3, lambda-(Mo K-alpha) = 0.71069 angstrom, mu = 0.106 mm-1, F(000) = 544, room temperature, final R = 0.032 for 1197 unique observed [F greater-than-or-equal-to 4-sigma(F)] reflections. (II) 1-(2,3-Dideoxy-erythro-beta-D-hexopyranosyl)thymine.dioxane complex, C11H16N2O5.-C4H8O2, M(r) = 344.36, monoclinic, C2, a = 17.23 (1), b = 7.651 (4), c = 13.401 (8) angstrom, beta = 101.14 (5)-degrees, V = 1734 (2) angstrom3, Z = 4, D(m) = 1.32, D(x) = 1.320 Mg m-3, lambda-(Mo K-alpha) = 0.71069 angstrom, mu = 0.098 mm-1, F(000) = 736, room temperature, final R = 0.048 for 1704 unique observed [F greater-than-or-equal-to 4-sigma(F)] reflections. In both structures the pyranose ring adopts a chair conformation flattened at the C(4') and C(1') apex for (I) and (II) respectively. For compound (I), with an intramolecular hydrogen bond between O(55')-H(1) and O(2), the H(1)-O(55')-C(55')-C(5') torsion angle is - sc (synclinal), while in compound (II), where no intramolecular hydrogen bonds are present, this torsion angle is in a + sc orientation. The N-glycosidic torsion angle chi is + sc and - ac (anticlinal) for (I) and (II) respectively. The dioxane molecule in (II) is suspected to be disordered. The packing of both crystals is determined by intermolecular hydrogen bonds. The conformational parameters are in accordance with the IUPAC-IUB Joint Commission on Biochemical Nomenclature [Pure Appl. Chem. (1983), 55, 1273-1280] guidelines.

Language

English

Source (journal)

Acta crystallographica: section C: crystal structure communications. - Copenhagen

Publication

Copenhagen : 1991

ISSN

0108-2701

DOI

10.1107/S0108270190010538

Volume/pages

47 :4 (1991) , p. 838-842