Glucose on reaction with HI gives n-hexane. What does it suggest about the structure of glucose?
Write any two reactions of glucose which cannot be explained by the open chain structure of glucose molecule.
What is essentially the difference between α-form of glucose and β-form of glucose? Explain.
The α-form of glucose and β-form of glucose can be distinguished by the position of the hydroxyl group on the first carbon atom.
In open chain α-glucose, the hydroxyl group on the first carbon atom is towards the right whereas, in the closed ring α-glucose, the hydroxyl group on the first carbon atom is below the plane of the ring.
On the other hand, in open chain β-glucose, β-glucose, the hydroxyl group on the first carbon atom is towards the left whereas, in the closed ring β-glucose, the hydroxyl group on the first carbon atom is above the plane of the ring.
The structures of open and cyclic α-form and β-form of glucose can be drawn as follows.