6-aza-2 `-deoxy-2 `-arabinofluorouridine, a 2 `-deoxyribonucleoside with an N-sugar conformation in the solid state and in solution

Abstract

In the title compound, 2-( 2- deoxy- 2- fluoro- beta- d- arabinofuranosyl)1,2,4- triazine- 3,5( 2H, 4H)- dione, C8H10FN3O5, the torsion angle of the N- glycosylic bond is anti [ chi = 125.37 ( 13)degrees]. The furanose moiety adopts the N- type sugar pucker ( T-3(2)), with P = 359.2degrees and tau(m) = 31.4degrees. The conformation around the C4' - C5' bond is antiperiplanar ( trans), with a torsion angle gamma of 177.00 ( 11)degrees. A network is formed via hydrogen bonds from the nucleobases to the sugar residues, as well as through hydrogen bonds between the sugar moieties.