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 (K 2 CO 3 , 18-Crown-6, DMF) afforded the target nucleosides 12 , 13 , 14 , and 15 . In addition, the antiviral evaluations against various viruses were performed.