The Amadori and Heyns rearrangements: Landmarks in the history of carbohydrate chemistry or unrecognized synthetic opportunities?

The Amadori and Heyns rearrangements have been known to carbohydrate chemis ts for decades. Following an outline of their historical development, a sur vey of the biological aspects, applications and alternative approaches will be given. Due to their nature, both reactions suffer from a variety of pre parative shortcomings; nonetheless, they are very useful bearing in mind th at no protecting group manipulations are required. Naturally occurring rear rangement products can play very important biological roles. For example, i n the Maillard reaction cascade, this type of rearrangement reactions appea r to be involved in the pathological effects of diabetes, Alzheimer's disea se and aging processes in general. Consequently, alternative means of synth etic access to the corresponding products have also been investigated. Both rearrangements appear to be highly underrated as useful methods for natura l products synthesis.