4-(purinyl bases)-substituted-1,3-dioxlanes

A 1,3-dioxolane derivative of the general formula (L), the geometric and optical isomers thereof and mixtures of those isomers:

• ##STR11## wherein:
• R.sub.1 is selected from the group consisting of hydrogen, an aliphatic acyl group having 2 to 16 carbon atoms, benzoyl and a benzoyl substituted in any position by a halogen, a lower alkyl, lower alkoxy, a nitro or a trifluoromethyl group;
• R.sub.2 is a heterocyclic radical selected from:
• ##STR12## wherein R.sub.3 is selected from the group consisting of hydrogen and lower alkyl radicals having from 1 to 3 carbon atoms;
• R.sub.4 is selected from the group consisting of hydrogen and lower alkyl or alkenyl radicals having from 1 to 3 carbon atoms;
• and
• R.sub.5 is selected from the group consisting of lower alkyl or alkenyl radicals having from 1 to 3 carbon atoms, fluoro and iodo.