The Synthesis of Partially-protected 2′-Deoxyribonucleotide Dimers by the Selective Phosphorylation of Stannylated Nucleosides

Abstract

Abstract A new method for the synthesis of the title compounds is described. The activation of the hydroxyl moieties of 5′-O-dimethoxytrityl and 3′,5′-unprotected 2′-deoxyribonucleosides, which were appropriately protected on their base residues, was done with bis(tributyltin) oxide in separate flasks. The resulting stannylated nucleosides were coupled with 2-chlorophenyl phosphorodichloridate to form the dimers with 3′→5′ internucleotide linkages in yields of more than 71%, along with the corresponding 3′→3′ isomers in yields of less than 10%. The method of Cashion et al. was also evaluated, in which up-to-date protecting groups were employed.