title: Synthesis of PS/PO-chimeric oligonucleotides using mixed oxathiaphospholane and phosphoramidite chemistry.
abstract: Chimeric oligonucleotides containing phosphodiester and phosphorothioate linkages have been obtained using the solid phase synthesis. The oligonucleotide parts possessing natural internucleotide phosphate bonds were assembled using commercially available nucleoside 3'-O-(2-cyanoethyl-N,N-diisopropylamino)phosphoramidites 7 whereas the phosphorothioate segment was built using nucleoside 3'-O-(2-thio-1,3,2-oxathiaphospholanes) 3. The oxidation steps, crucial for the conversion of phosphite linkages into the phosphate moieties, were conducted using tert-butylperoxy-trimethylsilane, and this reagent was not harmful to the diester phosphorothioate linkages. When P-diastereopure nucleoside 3'-O-(2-thio-1,3,2-oxathiaphospholane) monomers were employed the resulting chimeric backbone retained the P-stereoregularity of the phosphorothioate units.
authors.affiliation: Department of Bioorganic Chemistry, Center of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Łódź, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Radzikowska
authors.forename: Janina
authors.initials: J
authors.lastname: Baraniak
mesh_terms: D009711:Nucleotides / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D016877:Oxidants / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry*; D054735:Phosphorothioate Oligonucleotides / Q000737:chemistry*; D012266:Ribose / Q000031:analogs & derivatives* / Q000737:chemistry; D012821:Silanes / Q000737:chemistry
chemical_list: D009711:Nucleotides; D009943:Organophosphorus Compounds; D016877:Oxidants; D010710:Phosphates; D054735:Phosphorothioate Oligonucleotides; D012821:Silanes; C434797:oxathiaphospholane; C434331:phosphoramidite; D012266:Ribose