Partial acylation of cytidine and its 2'-C-methyl analogue as a tool to functionalize the ribonucleosidic 2',3'-cis-diol system

Precisely controlled conditions of acylation and 2’,3’-O-isomerization allowed to synthesize tripivaloyl derivatives of cytidine with free 2’- or 3’-hydroxyl group in a simple manner. Acylation of 2’-C-β-methylcytidine proceeded in a different way and resulted in the formation of tripivaloyl 2’-hydroxy nucleoside, or dipivaloyl 2’,3’-dihydroxy compound. All these products may be applied as key intermediates in the regioselective modification of 2’,3’-cis-diol system.