Oligonucleotides containing 2′-O-[2-(2,3-dihydroxypropyl)amino-2-oxoethyl]uridine as suitable precursors of 2′-aldehyde oligonucleotides for chemoselective ligation Original Research Article

2′-O-[2-(2,3-Diacetoxypropyl)amino-2-oxoethyl]uridine 3′-phosphoramidite was prepared and used in solid-phase synthesis to obtain oligonucleotides containing a 1,2-diol group, which may then be converted into a 2′-aldehyde group. The oligonucleotides were conjugated efficiently to various molecules by chemoselective ligation that involves an addition–elimination reaction between the 2′-aldehyde group and a suitable nucleophile, such as a hydrazine, a O-alkylhydroxylamine or an 1,2-aminothiol. The method was applied successfully to the conjugation of peptides to oligonucleotides at the 2′-position.