Collect. Czech. Chem. Commun. 1984, 49, 1592-1599

Regio and stereospecifity of solvent photoaddition to 5-fluorouracil and 1,3-dimethyl-5-fluorouracil

Nataša Zupančič, Marko Zupan and Boris Šket

Department of Chemistry and Jožef Stefan Institute, University of Edvard Kardelj, Ljubljana, Yugoslavia


Irradiation of 1,3-dimethyl-5-fluorouracil in methanol, ethanol, water and acetic acid, and 5-fluorouracil in water at λ = 253.7 nm resulted in the formation of two addition products. Regiospecifity was in all cases the same with functionalization at position 6 while the stereochemistry of addition dependend on the solvent. In water preferential trans addition proceeded while in acetic acid cis addition was predominant. Photoconversion of starting material was also twofold increased in acetic acid, compared to that in water.