Incorporation of a S-glycosidic linkage into a glyconucleoside changes the conformational preference of both furanose sugars Original Research Article

A glyconucleoside containing a thioglycoside linkage, namely 1-(3-S-β-d-ribofuranosyl-2,3-dideoxy-3-thio-β-d-ribofuranosyl)-thymine, has been prepared through condensation of a suitably protected derivative of 3′-thiothymidine with an activated ribose sugar. NMR has been used to study the conformation of the S-disaccharide and the unmodified O-disaccharide. A full pseudorotational analysis showed that for the S-disaccharide, the ribose and deoxy ribose sugars have a preference for the south and north pucker, respectively; which is the reverse of what is seen for the O-disaccharide.