A 1H nuclear magnetic resonance spectroscopic study of some N-methyl and N-acyl derivatives of guanosine. The structure of N,O(2′),O(3′),O(5′)-tetra-acetylguanosine

Abstract

Features of the ¹H n.m.r.spectra of guanosine and its N(1)-methyl, N(2)-methyl, N(2),N(2)-dimethyl, and N(7)-methyl derivatives in anhydrous [²H₆]dimethyl sulphoxide solution are discussed. Possible conclusions, based on the spectral data, relating to the tautomeric and conformational equilibria of these compounds are considered. An unsuccessful attempt to determine the site of N-acylation of guanosine by n.m.r. spectroscopy is described; however, the structure of N(2),O(2′),O(3′),O(5′)-tetra-acetyIguanosine has been established by a chemical method. Rates of deacylation of N(2)-acetyl- and N(2)-benzoyl-guanosines have been determined.