Synthesis of novel 3′-methyl-5′-norcarbocyclic nucleoside phosphonates as potential anti-HIV agents

Racemic synthesis of novel 3′-methyl-5′-norcarbocyclic nucleoside phosphonates 1a–c and 2 was performed using 4-hydroxy-2-methylcyclo-pent-2-enone as starting material. Direct coupling of the heterocyclic base involved a Mitsunobu reaction as key step. The compounds were evaluated for their antiviral properties, but none of them showed significant activity.