In this review different approaches to the synthesis of stereodefined metha
nephosphonate analogues of DNA (Oligo-PMe) are discussed, with special emph
asis on the stereoselective methods of preparation of (R-P) dinucleoside (3
',5')-methanephosphonates, which are building blocks for the preparation of
chimeric analogues of DNA. The scope of the use of methanephosphonate anal
ogues of DNA as potential therapeutic agents in antisense strategy is brief
ly presented in the introduction.