NEET 2025 · ChemistryPrevious Year Question
The total number of possible isomers (both structural as well as stereoisomers) of cyclic ethers of molecular formula \ce{C4H8O} is:
- A.(A) 10
- B.(B) 11✓
- C.(C) 6
- D.(D) 8
Correct Answer
(B) (B) 11
Solution & Explanation
\textbf{Answer:} (B) 11 \textbf{Solution:} \ce{C4H8O} has one degree of unsaturation; for a cyclic ether this is accounted for by the ring containing the oxygen. Enumerating all cyclic ethers (oxiranes, oxetanes, oxolane and their substituted forms) and then counting the additional stereoisomers from ring stereocentres (cis/trans and optical isomers) gives a total of 11 distinct isomers.
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