Circular dichroism and anomeric configuration assignment of benzimidazole C-nucleoside analogs

[Display omitted] ► Acid catalyzed dehydrative cyclization of 2-(L-arabino-tetritol-1-yl)benzimidazole gave 2-(β-L-erythrofuranosyl)benzimidazole ► The dehydrative cyclization took place with SN2 mechanism without inversion at C-1′. ► A correlation between the stereochemistry at the carbon atom α to the benzimidazole base moiety and the sign of the Cotton effect was obtained. ► This correlation is used for the assignment of the anomeric configuration. ► ECD proved to be a reliable tool for anomeric assignment. The circular dichroism of a series of acyclic polyhydroxyalkyl benzimidazole C-nucleoside analogs was correlated with the stereochemistry of the chiral carbon atom α to the benzimidazole base moiety. This correlation was used for the assignment of the anomeric configuration of 2-(β-l-erythrofuranosyl) benzimidazole C-nucleoside analogs without a need to have the other anomer on hand, in a similar manner to the correlation obtained for assignment of the anomeric configuration of triazole C-nucleoside analogs.