NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Chemistry
- Chapter
- Chapter
NEET 2026 · Chemistry · Chapter
The cyclic structure of D-(-)-fructose is known as a furanose...
The cyclic structure of D-(-)-fructose is known as a furanose structure. According to its structural representation, the furanose ring of fructose consists of:
Options
- AFive carbon atoms and one oxygen atom
- BFour carbon atoms and one oxygen atom
- CFive carbon atoms and zero oxygen atoms
- DFour carbon atoms and two oxygen atoms
Correct answer
B. Four carbon atoms and one oxygen atom
Step-by-step solution
D-(-)-fructose forms a five-membered cyclic structure known as a furanose ring.
This ring is formed by the intramolecular reaction between the hydroxyl group at C-5 and the ketone group at C-2, resulting in a hemiketal.
The five-membered ring consists of four carbon atoms (C-2, C-3, C-4, and C-5) and one oxygen atom.
Thus, the furanose ring of fructose contains four carbon atoms and one oxygen atom.
Answer: Four carbon atoms and one oxygen atom
This ring is formed by the intramolecular reaction between the hydroxyl group at C-5 and the ketone group at C-2, resulting in a hemiketal.
The five-membered ring consists of four carbon atoms (C-2, C-3, C-4, and C-5) and one oxygen atom.
Thus, the furanose ring of fructose contains four carbon atoms and one oxygen atom.
Answer: Four carbon atoms and one oxygen atom