title: Conformational studies of two isomeric ring-expanded purine nucleosides and their 5'-mono- and -diphosphate derivatives.
abstract: The nucleosides Ia and IIa exist in syn and anti conformations, respectively, both in solid state and solution. Compound Ia undergoes significant conformational change, accompanied by increased population of the anti conformer, upon conversion to the corresponding 5'-mono- and- diphosphate derivatives, whereas conformation of IIa remains reasonably constant between nucleoside and nucleotides. While Ia possessed the C2'-endo-C3'-exo geometry, IIa had the opposite C2'-exo-C3'-endo conformation. The C5' of the two nucleosides bore axial and equatorial conformations, respectively.
authors.affiliation: Department of Chemistry and Biochemistry, University of Maryland Baltimore County 21228.
authors.forename: R S
authors.initials: RS
authors.lastname: Hosmane
authors.forename: A
authors.initials: A
authors.lastname: Bhan
mesh_terms: D004121:Dimethyl Sulfoxide; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008958:Models, Molecular; D008968:Molecular Conformation; D011336:Probability; D011684:Purine Nucleosides; D011685:Purine Nucleotides; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013329:Structure-Activity Relationship
chemical_list: D011684:Purine Nucleosides; D011685:Purine Nucleotides; D004121:Dimethyl Sulfoxide