7‐Fluorotubercidin: a halogenated derivative of a naturally occurring nucleoside antimetabolite

The title compound systematic name: 4‐amino‐5‐fluoro‐7‐(β‐d ‐ribofuranosyl)‐7H‐pyrrolo2,3‐d]pyrimidine], C₁₁H₁₃FN₄O₄, exhibits an anti glycosylic bond conformation, with a χ torsion angle of −124.7 (3)°. The furanose moiety shows a twisted C2′‐endo sugar pucker (S‐type), with P = 169.8 (3)° and τ_m = 38.7 (2)°. The orientation of the exocyclic C4′—C5′ bond is +sc (gauche, gauche), with a γ torsion angle of 59.3 (3)°. The nucleobases are stacked head‐to‐head. The extended crystal structure is a three‐dimensional hydrogen‐bond network involving O—H...O, O—H...N and N—H...O hydrogen bonds. The crystal structure of the title nucleoside demonstrates that the C—C bonds nearest the F atom of the pyrrole system are significantly shortened by the electronegative halogen atom.