The Structure of 2′ (R)-Mercapto-2′-deoxyneplanocin A (Nucleosides and Nucleotides 48.)

Abstract

The molecular and crystal structure of 2′(R)-mercapto-2′-deoxyneplanocin A, C₁₁H₁₃N₅O₂S M.W.=279.32, has been determined by X-ray analysis. The space group is P2₁2₁2₁ with a=10.322(1), b=22.870(2), c=5.273(1)Å and z=4. The structure was solved by direct method, and least-squares refinement using 1806 reflections with |Fo| > 30(F) led to the final R value of 0.045. The sugar C(2′) atom is displaced by 0.35Å opposite to the base N(9), i.e., C(2′)-exo conformation and the torsion angle about the N(9)-C(1) bond is 26.3(4)° (anti conformation).