2′‐Deoxy‐7‐propynyl‐7‐deaza­adenosine: a DNA duplex‐stabilizing nucleoside

In the title compound, 2′‐deoxy‐7‐propynyl‐7‐deaza­adenosine, C₁₄H₁₆N₄O₃, the torsion angle of the N‐glycosylic bond is anti χ = ?130.7 (2)°]. The sugar pucker of the 2′‐deoxy­ribo­furanosyl moiety is C2′‐endo–C3′‐exo, ²T₃ (S‐type), with P = 185.9 (2)° and τ_m = 39.1 (1)°, and the orientation of the exocyclic C4′—C5′ bond is ?ap (trans). The 7‐substituted propynyl group is nearly coplanar with the heterocyclic base moiety. Mol­ecules of the nucleoside form a layered network in which the heterocyclic bases are stacked head‐to‐tail with a closest distance of 3.197 (1) Å. The crystal structure of the nucleoside is stabilized by three inter­molecular hydrogen bonds of types N—H? O, O—H? N and O—H? O.