Collect. Czech. Chem. Commun. 1982, 47, 2961-2968

Preparation of the 1-(2,5-anhydro-β-d-arabinofuranosyl) derivatives of cytosine and uracil and their cleavage with hydrogen bromide

Hubert Hřebabecký, Josef Brokeš and Jiří Beránek

Institute of Organic Chemistry and Biochemistry, Czechoslovak Academy of Sciences, 166 10 Prague 6


Anhydronucleoside Ia was prepared from chloroarabinofuranosylcytosine IIIc or from 2,2'-anhydro-1-(5-chloro-5-deoxy-β-D-arabinofuranosyl)cytosine by the action of a strongly basic ion exchanger. The anhydro derivative IIa was prepared from 2,2'-anhydro-1-(5-chloro-5-deoxy-β-D-arabinofuranosyl)uracil by treatment with aqueous solution of sodium hydroxide. The action of hydrogen bromide in dimethylformamide on 2',5'-anhydronucleosides Ia and IIa leads both to the cleavage of the anhydro bond under formation of the 5'-bromo derivatives IIIa and IVa and to the cleavage of nucleosidic bond. In case of the uracil derivative IIa, the α-arabinofuranosyl derivative V was also isolated after preceding acetylation. For unambiguous proof of the structure, an alternative synthesis of compound V was performed.