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

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 it 2'-aldehyde group. The oligonucleotides were conjugated efficiently to various Molecules by chemoselective ligation that involves all addition elimination reaction between the 2'-aldehyde group and a suitable nucleophile such as it hydrazine, a O-alkylhydroxylamine or in 1,2-aminothiol. The method was applied Successfully to the conjugation of peptides to oligonucleotides at the T-position, (c) 2005 Elsevier Ltd. All rights reserved.