A PROTECTED BIOTIN CONTAINING DEOXYCYTIDINE BUILDING BLOCK FOR SOLID-PHASE SYNTHESIS OF BIOTINYLATED OLIGONUCLEOTIDES

The synthesis of a modified 2′-deoxycytidine-3′-Ophosphoramidite carrying an N-t-butylbenzoyl protected biotin on a long polar spacer arm attached to the 4-N position is described. The presence of the bulky lipophilic t-butylbenzoyl protecting group enables the direct solid phase synthesis of biotinylated oligoribonucleotides and a variety of analogues in high yield without modification of the biotin moiety. Biotinylated antisense oligonucleotides incorporating this new derivative allow convenient isolation and purification of ribonucleic acid-protein complexes. The kinetics of biotin binding to streptavidin agarose is facilitated by the long polar spacer arm. © 1990 Oxford University Press.