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5'-Deoxy-5'-iodo-2': 3'-O-isopropylideneuridine (I) when treated with silver acetate in methanol gives 2': 3'-O-isopropylideneuridine, and base-catalysed methanolysis leads to 2': 3'-O-isopropylidene-O 2 - methyl-uridine which is converted by methanolic ammonia into 2': 3'-isopropylidene-isocytidine (IV). Acid- hydrolysis of (IV)yields isocytidine. Analogous transformation are described with 2': 3'-di-O-acetyluridine derivatives.

Uridine.5’ pyrophosphate has been synthesized by condensing 2’:3’-iso-propylidene 5’-iodo-5’-deoxyuridine with silver tribenzyl pyrophosphate and subsequently removing the protecting groups. The product, isolated as its barium salt, is identical with the “uridine diphoshate” obtained as a break down product of the naturally occurring coenzyme UDPG. In course of the work described use has been made of the observation that lithium chloride removes two benzyl groups from fully esterified pyrophosphates.

Monoacetylation of 5'-O'-acetyluridine yields a crystalline diacetate, from which by phosphorylation with dibenzyl phosphorochloridate followed by removal of protecting groups uridylic acid a is obtained. The diacetate is shown to be 3': 5'-Di-O-acetyl-2'-O-toluene-p-sulphonyluridine → O 2 : 2'-cyclouridine → 3-β-D-arobofuranosyl. Uridylic acid a is, therefore,uridine-2' phosphate. 3-β-D-Arobofuranosyl-uracil is identical with spongouridine, a nucleoside occuring naturally in sponges.