11.13 Reactions

Monosaccharides contain carbonyl functional group and alcohol functional groups, so it can be oxidized or reduced and can react with nucleophiles to form corresponding products.

11.13.1 Epimerization

In the presence of base, D-glucose may be converted into D-mannose via the removal of hydrogen at C-2 carbon followed by protonation of the enolate (Scheme 1).

Scheme 1

11.13.2 Enediol Rearrangement

The position of carbonyl group may shift via enediol intermediate under basic condition. For example, rearrangement of D-glucose gives D-fructose (Scheme 2).

Scheme 2

11.13.3 Reduction

The monosaccharide contains carbonyl group which can be reduced by the reducing agents such as NaBH 4 . Reduction of aldose forms one alditol and ketose forms two alditols (Scheme 3).

Scheme 3