7-Deaza-2'-deoxyguanosine.

In the title compound, 2-amino-7-(2-deoxy-beta-D-erythro-pentofuranosyl)-3,7-dihydropyrrolo[2,3-d]pyrimidin-4-one, C11H14N4O4, the N-glycosylic bond torsion angle, chi, is anti [-106.5 (3) degrees ]. The 2'-deoxyribofuranosyl moiety adopts the 3T4 (N-type) conformation, with P = 39.1 degrees and tau(m) = 40.3 degrees . The conformation around the exocyclic C-C bond is ap (trans), with a torsion angle, gamma, of -173.8 (3) degrees . The nucleoside forms a hydrogen-bonded network, leading to a close-packed multiple-layer structure with a head-to-head arrangement of the bases. The nucleobase interplanar O=C-C...NH(2) distance is 3.441 (1) A.