Compounds of the general formula: ##STR1## wherein A, B, and C are hydrogen, halogen, or azido; D is hydrogen, halogen, azido, or OH; A and B or C and D can be replaced with a double bond; R is an aldohexose, aldohexosamine, or N-acetyl aldohexosamine, R.sub.1 and R.sub.2 are hydrogen or alkyl groups of from C.sub.1 to C.sub.10 ; W is oxygen or sulfur; X is oxygen, sulfur, or CH.sub.2 ; Y is a purine or pyrimidine base, and Z is carbon, sulfur, or oxygen. Y can be any purine or pyrimidine base, natural or synthetic, which combines with a sugar to form a biologically active nucleoside. In combination with an appropriate pharmaceutical carrier, the compositions have enhanced activity or increased intracellular absorbment over the parent nucleoside as a function of the 5'-O-diphosphosugar. Another embodiment of the present invention is the enhancement of biologically active nucleosides into cells by preparing and administering the 5'-O-diphosphohexose, 5'-diphospho-N-acetylhexosamine or 5'-diphosphohexosamine derivative of the nucleoside. In the preferred embodiment for therapeutic use, the compounds are provided in a pharmaceutical carrier in an amount sufficient to exhibit as known in vitro or in vivo biological activity.