Open Access1, N 6 ‐Etheno‐2′‐deoxytubercidin hemihydrate
Author(s) -
Seela Frank,
Ding Ping,
Leonard Peter,
Eickmeier Henning,
Reuter Hans
Publication year - 2011
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
eISSN - 1600-5759
pISSN - 0108-2701
DOI - 10.1107/s0108270111005087
Subject(s) - conformational isomerism , chemistry , hydrogen bond , molecule , crystallography , stereochemistry , moiety , intermolecular force , pyrimidine , organic chemistry
The title compound [systematic name: 7‐(2‐deoxy‐β‐ d ‐ erythro ‐pentofuranosyl)‐7 H ‐imidazo[1,2‐ c ]pyrrolo[2,3‐ d ]pyrimidine hemihydrate], 2C 13 H 14 N 4 O 3 ·H 2 O or (I)·0.5H 2 O, shows two similar conformations in the asymmetric unit. These two conformers are connected through one water molecule by hydrogen bonds. The N‐glycosylic bonds of both conformers show an almost identical anti conformation with χ = −107.7 (2)° for conformer (I‐1) and −107.0 (2)° for conformer (I‐2). The sugar moiety adopts an unusual N ‐type (C3′‐ endo ) sugar pucker for 2′‐deoxyribonucleosides, with P = 36.8 (2)° and τ m = 40.6 (1)° for conformer (I‐1), and P = 34.5 (2)° and τ m = 41.4 (1)° for conformer (I‐2). Both conformers and the solvent molecule participate in the formation of a three‐dimensional pattern with a `chain'‐like arrangement of the conformers. The structure is stabilized by intermolecular O—H...O and O—H...N hydrogen bonds, together with weak C—H...O contacts.