A novel phosphoramidite for the synthesis of α-oxo aldehyde-modified oligodeoxynucleotides

The synthesis and use of a novel phosphoramidite derivatized by a bis[2-(tert-butyldisulfanyl)ethoxycarbonylamino]acetyl moiety for the synthesis of oligodeoxynucleotides modified at the 5′-end by an α-oxo aldehyde functionality is presented. Incorporation of the phosphoramidite reagent was performed after the automated solid-phase oligonucleotide synthesis. Simultaneous cleavage/deprotection of the oligodeoxynucleotides and unmasking of the α-oxo aldehyde group could be achieved using NaOH in aqueous methanol in the presence of dithiothreitol.