Résumé
Nucleosides analogues constitute an important family of therapeutic agents in the treatment of viral diseases. Among these compounds, carbocyclic nucleosides have interesting biological properties. The first chapter of this thesis is dedicated to a family of natural carbonucleosides, the neplanocins. We have presented their mode of action against S-adenosylhomocysteine hydrolase, as well as various syntheses of natural neplanocins and their enantiomers before reviewing their biological activities. In the second chapter, we described the first enantioselective synthesis of (―)-neplanocin B. The third chapter is devoted to the development of the synthesis of 3 '-halo-5’-norcarbonucleosides phosphonates as well as the evaluation of their antiviral activities.