Ulrike von Krosigk, S. Benner
Jun 1, 2004
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0
Influential Citations
13
Citations
Journal
Helvetica Chimica Acta
Abstract
The 6-aminopyrazin-2(1H)-one, when incorporated as a pyrimidine-base analog into an oligonucleotide chain, presents a H-bond donordonoracceptor pattern to a complementary DNA or RNA strand. When paired with the corresponding acceptoracceptordonor purine in oligonucleotides, the heterocycle selectively contributes to the stability of the duplex, presumably by forming a base pair of WatsonCrick geometry joined by a nonstandard H-bonding pattern, expanding the genetic alphabet. Reported here is a short, high yielding, β-D-selective synthesis of a 6-aminopyrazin-2(1H)-one nucleoside via the glycine riboside derivative 28. The key steps include a WittigHorner reaction of an appropriately protected ribose derivative (Scheme 10, 1921) followed by a Michael-like ring closure (Scheme 12, 301a and 321b). Thus, a variety of pyrazine nucleosides (Scheme 13) including the target 6-aminopyrazin-2(1H)-one riboside 1a, and its 5-methyl derivative 1b, 6-amino-5-methylpyrazin-2(1H)-one riboside, are obtained.