NMR study of some diastereomeric nucleoside-3'-thiophosphate derivatives in solution

The conformational properties of diastereomeric P-modified nucleotides are reported as reflected by different NMR parameters. Some conformational trends can be rationalized by consideration of the 3 J(C4′,P)and 3 J(C2′,P) coupling values of the isomers and the nature of the substituent on the phosphorus. Configurational assessment of the phosphorus is inferred from NOE experiments. The effects of temperature, solvent and size of substituents are presented.