Synthesis of -glycosyl amides: conformational analysis and evaluation as inhibitors of β-galactosidase from .

The synthesis of -glycosyl amides typically involves the use of glycosyl amines as direct precursors, resulting in low yields due to hydrolysis and the loss of stereocontrol through anomerization processes. In this study, a sequential synthesis of -glycosyl amides is proposed, employing glycosyl amines as intermediates obtained from glycosyl azides. Derivatives with , , or configurations were synthesized. Hexose derivatives were obtained under stereocontrol to give only the β anomer, while the derivatives provided a mixture of α and β anomers. Conformational analysis revealed that all β anomers adopted the C conformation, while α anomers were found in the C chair as the major conformer. After de--acetylation, the derivatives containing a galactose unit were evaluated as inhibitors of β-galactosidase from and were found to be moderate inhibitors.