The Donor-Acceptor-Acceptor Purine Analog: Transformation of 5-aza-7-deaza-1H-isoguanine (=4-aminoimidazo-[1,2-a]-1,3,5-triazin-2(1H)-one) to 2′-deoxy-5-aza-7-deaza-isoguanosine using purine nucleoside phosphorylase

✍ Scribed by Johannes J. Voegel; Michael M. Altorfer; Steven A. Benner

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: German
• Weight: 656 KB
• Volume: 76
• Category: Article
• ISSN: 0018-019X
• DOI: 10.1002/hlca.19930760520

✦ Synopsis

A new synthesis is reported for 4-aminoimidazo[l,2-~]-1,3,5-triazin-2( IH)-one ( = 5-aza-7-deaza-isoguanosine; S), a purine analog that, when incorporated into an oligonucleotide chain, presents a H-bond donor-acceptor-acceptor pattern to a complementary pyrimidine analog. A protected ribose derivative was coupled to 8 to yield 4-amin0-8-(8-~-ribofuranosyl)imidazo[ 1,2-~]-1,3,5-triazin-2(8H)-one ( = 5-aza-7-deaza-isoguanosine; 11) after deprotection, Alternatively, direct synthesis of both the ribo derivative 11 and the corresponding deoxyribo derivative 17 as the 8-D-anomers was achieved using the enzyme purine nucleoside phosphorylase in a one-pot reaction. This adapts a known synthetic approach to yield a new strategy for obtaining diastereoisomerically pure deoxyribonucleoside analogs on 1-gram scales.