Search

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.

A number of new acyl derivatives of cytosine and 3-methylcytosines are described. Acylation normally yields N 4 - monoacyl compounds which, in hot 80% acetic acid, yield large amounts of uracil derivatives. Exceptionally, benzoyl chloride can also yield a 1 : N 4 - dibenzoate from 3-methylcytosine and a tribenzoate from cytosine. Similarly, benzoylation of cytidine yields, according to conditions, either a tetrabenzoyl or pentabenzoyl derivative.