Phosphates and Acyl-esters of Nucleosides

Routine syntheses of nucleotides have not been covered. Syntheses of more unusual derivatives have included adenosine and uridine 5 -(1-amino)ethylphos-phonate, which are unaffected by alkaline phosphatase, and 5-fluoro-2 -deoxy-uridine 5 V-azidophenylphosphate, used as a photo-affinity label for thymidylate synthetase. 

Lichtenthaler, K. Kitahara, and W. Riess, Nucleic Acids Res Symp. 4th, Spec. PubU, 1978, 4, 115 Chem. Abs., 1979, 90,121 930i ). 

Takaku, T. Nomoto, Y. Sakamoto, and T. Hata, Chem. Lett., 1979, 1225. 

The regioselective deacylation of ribonucleosides is mentioned in Chapter 6 equilibration between 3,5- and 2, 5 -di-O-acyl derivatives can be achieved on silica gel allowing the 3, 5-isomer to be obtained as the major product on silica-gel column chromatography.  

A further report on the reactions of 5-azido-5-deoxy uridine (see Vol. 12, p. 166) describes its cyclization in presence of DDQ to give the bridged compounds (68) or (69).  

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