Rapid access to acyclic nucleosides via conjugate addition
作者:Stéphane Guillarme、Stéphanie Legoupy、Anne-Marie Aubertin、Cécile Olicard、Nathalie Bourgougnon、François Huet
DOI:10.1016/s0040-4020(03)00190-x
日期:2003.3
The synthesis of several acyclicnucleosides 5 and 6, analogs of penciclovir, was achieved by Michael addition as the key step. This reaction worked not only for the protected natural bases but even for the less nucleophilic deaza purine and deaza pyrimidine.
Acyclic, achiral enamide nucleoside analogues. The importance of the CC bond in the analogue for its ability to mimic natural nucleosides
作者:Asger B. Petersen、Michael Å. Petersen、Ulla Henriksen、Steen Hammerum、Otto Dahl
DOI:10.1039/b307394g
日期:——
The conformations of an acyclic, achiral enamide thymidine analogue 1 have been studied by model building and geometry calculations, as well as by NMR NOE and UV experiments. The results indicate that there are no significant barriers to rotation around any of the σ bonds, in particular the N1–C1′ enamide bond, and that the analogue should be able to accommodate conformations that mimic the conformations of natural nucleosides in A- and B-type helices quite well. For comparison the saturated analogue 2 has been prepared and built into oligonucleotides. It is shown that incorporation of 2 in oligonucleotides results in a much larger depression of the melting temperature (ΔTm
−10 to −12.5 °C) than does incorporation of 1
(ΔTm
−5 to −6.5 °C).