The Amadori and Heyns Rearrangements

2 FURTHER REACTIONS OE GLYCOSYLAMINES 6.2.1 The Amadori and Heyns Rearrangements  

The open-chain forms of glycosylamines (see Section 1.2.3) are Schiff bases and are labilised towards deprotonation of an adjacent carbon in much the same way as the open-chain forms of the sugars themselves. Reprotonation of the first-formed enamine on the carbon bearing the nitrogen atom will give an a-aminocarbonyl compound. The formation of a l-deoxy-l-amino-2-ketoses 

In contrast to the reactions of the straight-chain forms of reducing sugars, however, the carbanion-like reactions of glycosylamines are most rapid near neutrality. This is because the conjugate acids of the Schiif bases are much better 

Reactions of aldoses with amines can be stopped conveniently at the 1-amino-l-deoxy-2-ketose stage if the amine is an arylamine such as aniline (pifa 4.6) and the reaction is carried out in buffered weakly acid medium (such as glacial acetic 

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Eder B, see Wrodnigg TM (2001) The Amadori and Heyns Rearrangements Landmarks in the History of Carbohydrate Chemistry or Unrecognized Synthetic Opportunities 215 115-175 Edwards DS, see Liu S (2002) 222 259-278... 

Wrodnigg, T. M., Eder, B. The Amadori and Heyns rearrangements Landmarks in the history of carbohydrate chemistry or unrecognized synthetic opportunities Top. Curr. Chem. 2001, 215,115-152. 

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