Synthesis of conformationally locked carbocyclic nucleosides built on a thiabicyclo[3.1.0]hexane system as a pseudosugar surrogate

Abstract

The synthesis of prototype models of purine and pyrimidine carbanucleosides built on a 6-thiabicyclo[3.1.0]hexane system as pseudosugar moiety has been investigated. These pyrimidine carbanucleosides proved to be very stable compounds, in contrast to the parent epoxy analogs, which experienced epoxide ring-opening due to intramolecular enol base attack. In addition, as the synthesis of a thiirane moiety fused to a five-membered ring is not a trivial synthetic task, validation and optimization of the existing methods for episulfide preparation were required to access the committed synthetic precursor of the title compounds: (±)-(1RS,2RS,5SR)-6-thiabicyclo[3.1.0]hexan-2- ol, compound 28. © Wiley-VCH Verlag GmbH & Co. KGaA, 2006.