Synthesis and evaluation of 2'-substituted cyclobutyl nucleosides and nucleotides as potential anti-HIV agents

A series of 2'-substituted cyclobutyl nucleoside analogs were efficiently prepared by constructing the core cyclobutyl ring using different [2+2] cycloaddition approaches. The triphosphate derivative of a cyclobutyl nucleoside was also synthesized and evaluated against wild-type and mutant HIV reverse transcriptases (RT). Whereas the nucleoside analogs were inactive against HIV-1 in culture, the nucleotide showed good activity not only against wild-type and recombinant HIV RT (IC(50)=4.7, 6.9 microM), but also against the M184I and M184V mutants (IC(50)=6.1, 6.9 microM) in cell-free assays.