C -Glycopyranosyl aldehydes: emerging chiral synthons in organic synthesis.

Herein, we have summarized the vast array of synthetic processes that have been developed for the synthesis of C -glycopyranosyl aldehydes and diverse C -glycoconjugates derived from them by covering the literature reported from 1979 to 2023. Notwithstanding its challenging chemistry, C -glycosides are considered stable pharmacophores and are used as important bioactive molecules. The discussed synthetic methodologies to access C -glycopyranosyl aldehydes take advantage of seven key intermediates, viz. allene, thiazole, dithiane, cyanide, alkene, and nitromethane. Furthermore, the integration of complex C -glycoconjugates derived from varied C -glycopyranosyl aldehydes involves nucleophilic addition/substitution, reduction, condensation, oxidation, cyclo condensation, coupling, and Wittig reactions. In this review, we have categorized the synthesis of C -glycopyranosyl aldehydes and C -glycoconjugates on the basis of the methodology used for their synthesis and on types of C -glycoconjugates, respectively.