Degradation of the osides

Condensation with hydroxylamine

The reaction of hydroxylamine $ NH_2OH $ with aldoses provides an aldoxime:

The reaction of hydroxylamine $ NH_2OH $ with ketoses provides a ketoxime:

Application: Degradation of aldoses

The dehydration of aldoxime leads to the corresponding cyanohydrin:

Cyanohydrin, by returning the →        addition reaction of $ HCN $ may be transformed into the corresponding aldose truncated of one $ C $ atom :

Exercise

Which substance is obtained by exercing twice the previous degradations on D-glucose?

Answer (Review →    this page ) : D-glucose →    .......... →    ..........