The Amadori Rearrangement

TLDR: This chapter discusses the reaction that is the isomerization of an aldosylamine to a 1-amino-1-deoxy-2-ketose configuration, named after Amadori by Kuhn and Weygand, for this rearrangement was the first to demonstrate that condensation of D-glucose with an aromatic amine would yield, according to experimental conditions, two structurally different isomers.

Abstract: Publisher Summary This chapter discusses the reaction that is the isomerization of an aldosylamine to a 1-amino-1-deoxy-2-ketose. This rearrangement was named after Amadori by Kuhn and Weygand, for Amadori was the first to demonstrate that condensation of D-glucose with an aromatic amine ( p -phenetidine, p -anisidine, or p -toluidine) would yield, according to experimental conditions, two structurally different isomers, which are not members of an α, β anomeric pair. Amadori did not realize that an isomerization (“rearrangement”) from an aldose to a ketose configuration had occurred. However, he did discern (by change of optical rotation in acid solution) that one isomer is much more labile than the other toward hydrolysis and more susceptible to decomposition on standing in the solid state in air. He recognized correctly that the labile isomer is the N -substituted glucosylamine, but he mistakenly thought that the stable isomer was a compound of the Schiff-base type. Authentic crystalline products of the Amadori rearrangement have so far been obtained only from D-glucose, D-mannose, and 5- O -trityl-D-xylose as the sugar components. Occurrence of the rearrangement (or at least 1, 2-enolization of the N -substituted glycosylamine) was demonstrated indirectly, however, by isolation and characterization of crystalline epimeric hydrogenation products derived from D- and L-arabinose and also from D-xylose.