SOLID-PHASE SYNTHESIS OF OLIGODEOXYNUCLEOTIDES CONTAINING 4-ALKOXYTHYMIDINE RESIDUES

Immobilized and fully protected oligodeoxynucleotides containing a 4-( 1,2,4-triazolyl)-thymidine residue at a predetermined position were pr epared according to a well-established phosphite triester methodology using 2-cyanoethyl phosphoramidites of a 4-(1,2,4-triazolyl)-substitut ed thymidine and standard protected nucleosides. Treatment of the immo bilized oligomer with methanol, ethanol or n-propanol in the presence of DBU at 50-degrees-C gave the corresponding oligonucleotides contain ing 4-methoxy, 4-ethoxy- or 4-n-propoxythymidine residue.