Incorporation of 2′-Deoxysangivamycin in DNA Duplexes: The Conversion of a Pyrrolo[2, 3-d]Pyrimidine Nitrile to a Carboxamide upon Oligonucleotide Deprotection

Abstract

Oligonucleotides containing 2′-deoxysangivamycin are described. The phosphoramidite of 2′-deoxytoyocamycin was prepared and used in solid-phase synthesis. Upon deprotection the pyrrolo[2, 3-d]pyrimidine nitrile residues were converted to carboxamides. According to the T _m-measurements the 7-carboxamido group of the 7-deazaadenine moiety stabilizes the DNA duplex significantly.