Are 5′-O-Carbamate-2′,3′-dideoxythiacytidine New Anti-HIV and Anti-HBV nucleoside Drugs or Prodrugs?

Are 5′-O-Carbamate-2′,3′-dideoxythiacytidine New Anti-HIV and Anti-HBV nucleoside Drugs or Prodrugs? Synthesis and anti-HIV activity of novel 2′,3′-dideoxy-3′-thiacytidine prodrugs Potent Nonclassical Nucleoside Antiviral Drugs Based on the N,N-Diarylformamidine Concept New 3‘-Azido-3‘-deoxythymidin-5‘-yl O-(ω-Hydroxyalkyl) Carbonate Prodrugs:  Synthesis and Anti-HIV Evaluation Amidate Prodrugs of Deoxythreosyl Nucleoside Phosphonates as Dual Inhibitors of HIV and HBV Replication Synthesis and Biological Evaluation of Fatty Acyl Ester Derivatives of (−)-2′,3′-Dideoxy-3′-thiacytidine New 3‘-Azido-3‘-deoxythymidin-5‘-yl O-(4-Hydroxyalkyl or -Alkenyl or -Alkylepoxide) Carbonate Prodrugs:  Synthesis and Anti-HIV Evaluation Novel 3‘-C/N-Substituted 2‘,3‘-β-<scp>d</scp>-Dideoxynucleosides as Potential Chemotherapeutic Agents. 1. Thymidine Derivatives:  Synthesis, Structure, and Broad Spectrum Antiviral Properties Potential prodrug derivatives of 2',3'-didehydro-2',3'-dideoxynucleosides. Preparations and antiviral activities Synthesis and antiviral activity of 2′-deoxy-2′-fluoro-2′-C-methyl-7-deazapurine nucleosides, their phosphoramidate prodrugs and 5′-triphosphates