Monosaccharides are reduced to their corresponding alcohols by reducing agents such as sodium amalgam or by hydrogen under high pressure in the presence of a catalyst. For example, aldoses yield the following alcohols:

D-glucose  D-sorbitol
D-galactose  D dulucitol
D-mannose  D-mannitol

Similarly, ketoses also yield two alcohols due to the formation of a new asymmetric carbon in the C-2 position.

Fructose  D-mannitol + D-sorbitol

The following are the important reactions:

• Reduction of glycerose to glycerol
• Reduction of ribose to ribitol, which forms a part of riboflavin
• Reduction of glucose to ascorbic acid (vitamin C)