10.1016/S0040-4039(01)80782-6
The research focuses on the synthesis of dinucleoside phosphorodithioates and phosphorothioates, which are analogues of oligonucleotides with potential applications as antiviral agents and in studies involving interactions with nucleic acids and proteins. The purpose of the study is to develop an alternative and convenient approach to synthesizing these analogues using protected nucleoside 3'-phosphonodithioates as starting materials. The researchers successfully converted 5'-O-(9-phenylxanthen-9-yl)thymidine into its 3'-phosphonodithioate derivative and further into dinucleoside phosphonothioate and dinucleoside phosphorodithioate with good overall yields. Key chemicals used in the process include triethylammonium salt, 3'-O-acetylthymidine, pivaloyl chloride, and sulfur. The study concludes that the procedure is potentially applicable to the synthesis of phosphorodithioate analogues of oligodeoxyribo- and oligoribo-nucleotides, both in solution and on solid supports, and that the synthesized dinucleoside phosphorodithioate (6a) is resistant to digestion by snake venom phosphodiesterase, bovine spleen phosphodiesterase, and nuclease PI.