Synthesis and Anti-HIV Activity of Guanine Modified Fluorinated Acyclic Nucleoside Phosphonate Derivatives.

The preparation of an unprecedented series of nucleobase modified 3-fluoro-2-(phosphonomethoxy)propyl (FPMP) acyclic nucleosides in both their (R) and (S) enantiomerically pure forms is described. The synthesis focuses on a Mitsunobu alkylation reaction to construct the C-N(9) bond between a chiral fluorinated side-chain residue and 6- or 7-modified guanine analogs. Prodrugs of FPMP-7-deazaguanine were also synthesized by derivatization of the corresponding phosphonic acid functionality with (bis)diamyl aspartate amidate groups, leading to moderate activity against human immunodeficiency virus type 1 (HIV-1).