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

Abstract

In the title compound, 2'-deoxy-7-propynyl-7-deazaadenosine, C14H16N4O3, the torsion angle of the N-glycosylic bond is anti [chi = -130.7 (2) degrees ]. The sugar pucker of the 2'-deoxyribofuranosyl moiety is C2'-endo-C3'-exo, 2T3 (S-type), with P = 185.9 (2) degrees and tau(m) = 39.1 (1) degrees , 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) A. 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.

7-Cyclopropyl-2′-deoxytubercidin: a carbocyclic side-chain derivative of 7-deaza-2′-deoxyadenosine

“…The length of the glycosylic bond N9-C1 0 of (I) is 1.446 (2) Å , which is within the same range as those observed for (IIa) [1.438 (4) Å ; Abola & Sundaralingam, 1973], (IIb) [1.449 (2) Å ; Zabel et al, 1987] and (III) [1.457 (3) Å ; Seela et al, 2006].…”

“…The three 2 0 -deoxyribonucleosides, (I), (IIb) and (III), crystallize in the same space group, i.e. orthorhombic P2 1 2 1 2 1 (Zabel et al, 1987;Seela et al, 2006), while the space group is monoclinic P2 1 for the parent ribonucleoside tubercidin, (IIa) (Stroud, 1973).…”

“…shows an anti conformation, with the torsion angle = À108.7 (2) . The related nucleosides (IIa) and (IIb), as well as (III), also adopt values corresponding to the anti conformation [ = À112.8 (4) for (IIa) (Abola & Sundaralingam, 1973), = À104.4 (2) for (IIb) (Zabel et al, 1987) and = À130.7 (2) for (III) (Seela et al, 2006)].…”

“…In the meantime, single-crystal X-ray studies of several 7-substituted tubercidin derivatives have been reported (Seela et al, 2005(Seela et al, , 2006(Seela et al, , 2008. For that reason, we became interested in the X-ray single-crystal structure of the title 2 0 -deoxytubercidin derivative, (I), bearing a cyclopropyl group in the 7-position and we wished to compare its solid-state structure with those of the closely related nucleosides tubercidin, (IIa) (Stroud, 1973;Abola & Sundaralingam, 1973), 2 0 -deoxytubercidin, (IIb) (Zabel et al, 1987), and 2 0 -deoxy-7propynyltubercidin, (III) (Seela et al, 2006).…”

Advances in the Synthesis of 7-Deazapurine - Pyrrolo[2,3-d]pyrimidine 2-Deoxyribonucleosides Including D- and L-Enantiomers, Fluoro Derivatives and 2,3-Dideoxyribonucleosides

“…Single crystal X-ray analyses of 7-deaza-2'-deoxy-7-propynylguanosine (91b) and 7-deaza-2'-deoxy-7-propynyladenosine (92b) were reported by our laboratory [103,104] (Fig. 6).…”