7-deaza-2 `-deoxyisoguanosine adopts the form of an N1-H,2-keto tautomer

Abstract

The structure of the title hydrate [4-amino-7-(2-deoxy-beta-D-erythro-pentofuranosyl)-3,7-dihydro-2H-pyrr olo[2,3-d]pyrimidin-2-one hydrate, C11H14N4O4. H2O], an analogue of 2'-deoxyisoguanosine, was determined by single-crystal X-ray diffraction. The glycosylic torsion angle [chi = -118.3(3)degrees] is in the anti conformation range and the sugar ring adopts a C1'-exo pucker. The molecule shows the N1-H,2-keto-6-amino tautomeric form in the solid state.