Conformationally restricted 2-substituted wyosine derivatives. 1H, 13C, and 15N NMR study

It was found by 1H, 13C and 15N NMR study that substitution of 4,9-dihydro-4,6-dimethyl-9-oxo-3-(2',3',5'-tri-O-acetyl-beta-D-ribofuranosyl) imidazo 1,2-a]purine (wyosine triacetate, 1) at C2 position with electronegative groups CH30 and C6H5CH2O results in a noticeable electron distribution disturbance in the "left-hand" imidazole ring and a significant increase in the North conformer population of the sugar moiety.