New Acyclic Purine Nucleoside Analogues Containing Exocyclic Pyrrolo Moiety: Synthetic, NMR and X-ray Crystal Structure Studies

摘要

The synthesis of novel 6-(N-pyrrolyl)purine nucleoside analogues containing acyclic side chains attached to the purine ring at N-9 is described. The structures were determined by ~1H and ~(13)C NMR on the basis of chemical shifts, substituent induced shifts, C-H coupling constants and connectivity in the COSY, NOESY and HET-COR spectra. Unequivocal proof for the stereostructure of 6 was obtained by its X-ray crystallographic analysis. Geometrical data from X-ray structural analysis showed that the two 6-(N-pyrro-lyl)purine rings involved in the skeleton of 6 are anti-disposed but not centrosymmetric with respect to the central aliphatic bridge.%Opisana je sinteza novih nukleozidnih analoga 6-(N-pirolil)purina koji sadržavaju acikličke lance pripojene na purinsku jezgru u položaju N-9. Strukture su određene spektroskopijom ~1H i ~(13)C NMR na temelju kemijskih pomaka, pomaka induciranih supstituentima, konstanata sprege C-H i povezanosti u spektrima COSY, NOESY i HETCOR. Nedvojbeni dokaz za stereostrukturu spoja 6 dobiven je rentgen-skom strukturnom analizom. Geometrijski podaci iz te analize pokazuju da su dva 6-(N-pirolil)purinska prstena, koji sačinjavaju kostur spoja 6, međusobno u anti-položaju, ali ne i centrosimetrični u odnosu na središnji alifatski most.