Synthesis and antiviral evaluation of hydantoin analogues of AZT.

3'-Azidonucleosides 4 have been synthesized by condensation of silylated (Z)-5-ethylidenehydantoin and (Z)-5-benzylidenehydantoin with methyl 3-azido-5-O-tert-butyldiphenylsilyl-2,3-dideoxy-D-erythro-pento furanoside (3). The nucleosides 4 were deblocked on treatment with tetrabutylammonium fluoride. The ethylidene group isomerized from Z to E configuration during the nucleoside synthesis. The new nucleosides did not show any appreciable activities against HIV-1 or HSV-1.