Researchers from ZIOC RAS succeeded in suppression of acyl groups migration in the reactions of partially protected carbohydrates derivatives azidation

Azidoalkyl-substituted aglycones are widely used in carbohydrate chemistry as precursors of aminoalkyl aglycones, as well as in click-reactions to produce various glycoconjugates. However, azidation through nucleophilic substitution, which is commonly applied in organic synthesis, is not always suitable for partially protected carbohydrate derivatives due to the possibility of side process of O-acyl protective groups migration.

During investigations in the field of Janus glycosides, researchers from the Zelinsky Institute had difficulties in the synthesis of partially protected lactosides with an azido group in the terminal position of the aglycon caused by the migration of O-benzoyl protective groups. To solve the problem, the researchers developed a simple and reliable method of suppression of this side process: the addition of n-butyl formate as an interceptor of bases traces present in sodium azide, significantly suppressed the migration of O-benzoyl groups and at the same time did not significantly affect the process of substitution of chlorine atom with an azido group. The developed synthetic approach is expected to be be used to suppress the migration of protective groups in other reactions involving partially acylated carbohydrates and related compounds.

Source:

Elena V. Stepanova , Alexander I. Zinin, Polina I. Abronina, Alexander O. Chizhov, Leonid O. Kononov, Azidation of Partially Protected Carbohydrate Derivatives: Efficient Suppression of Acyl Migration, Synlett, 2020, accepted manuscript, DOI: 10.1055/s-0040-1707137.