Chemistry Letters, Vol.38, No.2, 174-175, 2009
Synthesis of 4-Thiopseudoisocytidine and 4-Thiopseudouridine as Components of Triplex-forming Oligonucleotides
In this paper, we report convenient methods for the synthesis of 4-thiopseudoisocytidine (s(4) psi iC) and 4-thiopseudouridine (S-4 Psi). H-1 NMR spectral analysis of these modified nucleosides showed that both s(4) Psi and s(4) psi iC prefer C3'-endo ribose puckering. These conformational properties are favorable for the stabilization of triplex formation.