ACIDIC HYDROLYSIS OF 6-SUBSTITUTED 9-(2-DEOXY-β-D-ERYTHRO-PENTOFURANOSYL)PURINES AND THEIR 9-(1-ALKOXYETHYL) COUNTERPARTS: KINETICS AND MECHANISM.

Article abstract of DOI:10.1016/S0040-4020(01)90052-3

The rate constants for the hydrolysis of several 6-substituted 9-(2-deoxy-β-D-erythro-pentofuranosyl)purines and 9-(1-alkoxyethyl)purines have been measured at different concentrations of oxonium ion.The effects that varying the polar nature of the alkoxy group exerts on the hydrolysis of unsubstituted 9-(1-alkoxyethyl)purines are interpreted to indicate that the reaction proceeds by a rate-limiting departure of the protonated base moiety with a concomitant formation of an alkoxyethyl oxocarbenium ion.The same mechanism is applied to the hydrolysis of 9-(2-deoxy-β-D-erythro-pentofuranosyl)purines by comparing the influences that 6-substituents have on the reactivity of these compounds and their 9-(1-alkoxyethyl) counterparts.No sign of anomerisation was detected, when the hydrolysis of 2'-deoxyadenosine was followed by ¹H NMR spectroscopy.