Synthesis of the carbocyclic analogue of the antiviral nucleoside (E)-5-(2-bromovinyl)-2′-deoxyuridine

The cyclopentanecarboxylic acid (1) was converted via the isocyanate (2) and the urea (5) into carbocyclic uridine (12). Similarly, the α- and β-epimers of carbocyclic 2′-deoxyuridine, (19a) and (19b), were synthesized from the acids (13). Compounds (19b) and (19a) were further modified to afford carbocyclic (E)-5-(2-bromovinyl)-2′-deoxyuridine (25b) and its α-epimer (25a), respectively.