SSC CHSL 2024 PYQ — Question 31

The correct answer is option 2 i.e. Pyran is a cyclic organic compound, with one oxygen atom and five carbon atoms in the ring.

The six-membered cyclic structure of glucose is called a pyranose structure because:

1. Glucose forms a cyclic hemiacetal by reacting its aldehyde group with a hydroxyl group.
2. The resulting ring contains five carbon atoms and one oxygen atom, forming a six-membered ring.
3. This six-membered ring structure resembles pyran, a six-membered heterocyclic compound with one oxygen atom.
4. Hence, the glucose ring is called a pyranose.
5. Pyranose can exist in alpha or beta forms depending on the position of the hydroxyl group.
6. Pyranose structures are common in sugars like glucose and fructose.