Dissociation of O6-(p-Methoxybenzyl)guanosine in Aqueous Solution to Yield Guanosine, p-Methoxybenzylguanosines, and 4-(p-Methoxybenzyl)-5-guanidino-1-β-D-ribofuranosylimidazole

Article abstract of DOI:10.1021/ja00408a035

The kinetics and products of O⁶-(p-methoxybenzyl)guanosine (1) decomposition in MeOH/H2O (5:95) at 40 deg C have been examined over a wide range of pH values.The decomposition is acid catalyzed below pH 7, but over the pH range 8-13 the rate of decomposition is nearly pH independent.In addition to guanosine, N²-(p-methoxybenzyl)guanosine, 4-(p-methoxybenzyl)-5-guanidino-1-β-D-ribofuranosylimidazole, and 7-(p-methoxybenzyl)-, 1-(p-methoxybenzyl)-, and 8-(p-methoxybenzyl)guanozine are produced by the decomposition of 1.Yields for these nucleoside products are pH dependent.An ionic mechanism involving dissociation of 1 to a p-methoxybenzylating agent which reassociates with either anionic and/or neutral guanosine largely accounts for the pH dependence of the product distributions.