Nucleosides and nucleotides. 162. Facile synthesis of 5′-5′-linked oligodeoxyribonucleotides with the potential for triple-helix formation

The facile synthesis of 5′-5′-linked oligodeoxyribonucleotides (ODNs) with the potential for triple-helix formation is described. ODNs containing 5-trifluoroethoxycarbonyl-2′-deoxyuridine were treated with several diaminoalkanes to give ODNs carrying amino-linkers. After conversion of the amino-linkers in the ODNs to mercapto-linkers, two ODNs were linked by a disulfide bond to give 5′-5′-linked ODNs. The thermal stability of these ODNs with target duplexes was also studied.