Simple synthesis and anti-HIV activity of novel cyclopentene phosphonate nucleosides.

A very simple synthetic route for novel cyclopentene phosphonate nucleosides is described. The characteristic cyclopentene moiety 6 was constructed via a ring-closing metathesis of divinyl 5, which could be readily prepared from diethylmalonate. The condensation of the mesylate 11 with nucleobases (A, C, T, U) under nucleophilic substitution conditions (K2CO3, 18-Crown-6, DMF) afforded the target nucleosides 12, 13, 14, and 15. In addition, the antiviral evaluations against various viruses were performed.