Ketose to Corresponding Aldose Conversion
The conversion of a ketose (like D-Fructose) into its corresponding aldoses (D-Glucose and D-Mannose) involves a series of redox reactions that reconfigure the carbon backbone.
Chemical Mechanism Steps
- Reduction: The ketose is reduced using Na-Hg (sodium amalgam) in a trace acidic environment. This creates a new asymmetric carbon center, resulting in two distinct polyhydric alcohols.
- Oxidation: These polyhydric alcohols are then oxidized with HNO3 to produce monobasic aldonic acids.
- Lactonization: The aldonic acids are treated with dilute HCl to form γ-lactones.
- Final Reduction: The lactones are reduced using LAH (Lithium Aluminum Hydride) or Na-Hg in a weakly acidic solution to yield the final aldoses, which are isomers of the original ketose.