Approach to the synthesis of natural and modified oligonucleotides by the phosphotriester method using O-nucleophilic intramolecular catalysis.

An approach to the solid phase synthesis of natural and modified oligonucleotides using phosphotriester technique has been developed. Particularly, this method allows the synthesis of ribo- and deoxyribo-oligonucleotides containing various 2'-modified mononucleotides as well as stereodefined nucleotide phosphorothioate analogues.