Reaction of cytidine with cyanopropargylic alcohols: Synthesis of functionalized cytidine cyclic ketals

摘要

Cytidine reacts with one or two molecules of cyanopropargylic alcohols under mild conditions (K2CO3, DMF, 20-25? °C, 10-48 h) by the hydroxy groups of the ribose moiety to afford representatives of the two novel families of cytidine cyclic ketals. The first ones (53-76% yields) are formed with participation of the two vicinal hydroxyl groups (at 2′,3′-cis-positions) only. The second ones (7-21% yields) represent the adducts of cytidine with two molecules of cyanopropargylic alcohols involving all the three hydroxyl groups.