NMR Conformational Study Reveals that S-C-N Anomeric Effect in Thionucleosides Is Weaker than O-C-N Anomeric Effect in Natural Nucleosides

摘要

The comparative analysis by NMR and ab initio calculations of the energetics of North<=>South pseudorotational equilibrium in 4'-thio- nucleosides and in their natural 4'-oxo counterparts has shown that S-C-N anomeric effect in the former is weaker than O-C-N anome- Ric effect in the latter.