8-Azaadenosine and Its 2′-Deoxyribonucleoside: Synthesis and oligonucleotide base-pair stability

✍ Scribed by Frank Seela; Ingo Münster; Uwe Lüchner; Helmut Rosemeyer

• Book ID: 102858012
• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: German
• Weight: 995 KB
• Volume: 81
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19980810527

✦ Synopsis

The synthesis of 8-azaadenosine (la; z8A) has been performed by SnCI,-catalyzed glycosylation of X-azaadeninc (4) with I ,2,3.5-tetra-O-acetyl-/7-~-rihofuranose (5). followed by the separation of the regioisomers 6 and 7 and subsequent deacetylation. The ribonucleoside la as well as its 2.'-deoxy derivative Ib (z8AA,) wcrc converted into oligonucleotide building blocks ~ the phosphonate 2 as well as the phosphoramidites 3 and 19. They were uscd to preparc the oligoribonucleotide (z*A-U), and oligodeoxyribonucleotides. The T, values and the thermodynamic data of duplex formation of the modified duplexes showed no significant changes compared to those containing A, or A residues. This indicates that the stereoelectronic effect of the 8-azaadenine base which was found for the monomeric nucleoside has only a minor influence on the duplex stability. ' ) Measured in (D,)DMSO; 303 K. b, Purine numbering. ' ) Systematic numbering. d, Superimposed by DMSO. e, Superimposed by 4,4-dimethoxytrityl.