Stereoselective Syntheses of Retro‐Isomers of N‐Glucoasparagine

A new type of linkage between the anomeric center of a pyranose and an amino acid is represented by the C‐glycosidic amide bond (shown on the right). It was formed by coupling heptonic acids with a β‐aminoalanine derivative. Both the α and the β anomers were prepared selectively. (Figure Presented.)