2′-Deoxy-β-D-ribofuranosides of N6-Methylated 7-Deazaadenine and 8-Aza-7-deazaadenine: Solid-phase synthesis of oligodeoxyribonucleotides and properties of self-complementary duplexes

✍ Scribed by Frank Seela; Klaus Kaiser; Uwe Bindig

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: German
• Weight: 861 KB
• Volume: 72
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19890720503

✦ Synopsis

The syntheses of 7-deaza-N6-methyladenine N9-(2'-deoxy-~-o-ribofuranoside) (2) as well as o f 8-aza-7-deaza-N6-methyladenine N8-and N9-(2'-deoxyribofuranosides) (3 and 4, resp.) are described. A 4,4'-dimethoxytritylation followed by phosphitylation yielded the methyl phosphoramidites 12-14. They were employed together with the phosphoramidite of 2'-deoxy-N6-methyladenosine (15) in automated solid-phase oligonucleotide synthesis. Alternating or palindromic oligonucleotides derived from d(A-T), or d(A-T-G-C-A-G-A*-T-C-T-G-C-A) but containing one methylated pyrrolo [2,3-d]pyrimidine or pyrazolo[3,4-d]pyrimidine moiety in place of a N6-methylaminopurine (A*) were synthesized. Melting experiments showed that duplex destabilization induced by a Nb-Me group of 2'-deoxy-N6-methyladenosine is reversed by incorporation of 8-aza-7-deaza-2'-deoxy-N6methyladenosine, whereas 7-deaza-2'-deoxy-N6-methyladenosine decreased the T, value further.