[Synthesis of oligoribonucleotides via ribonucleoside-H-phosphonates]

The synthesis of oligoribonucleotides via 5'-O-dimethoxytrityl-2'-E-tetrahydropyranyl-N-acylribonucleoside 3'-H-phosphonates is described. With these synthones and pivaloyl chloride as condensing agent, the synthesis of CpC and GpA in solution and the polymer support synthesis of (Up)4U and (Up)5C in manual variant and at the automatic synthesizer "Victoria-4M" was performed. The obtained oligonucleotide-H-phosphonates were oxidized to phosphates both with usually employed aqueous iodine solution and with of CCl4-Et3N-H2O (the Todd-Atherton reaction).