The IUPAC name of the following compound is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Cyclohexanecarbaldehyde
The compound is a cyclohexane ring carrying one –CHO group, \( \ce{C6H11CHO} \). For a –CHO group on a ring the suffix carbaldehyde is added to the name of the ring: cyclohexane + carbaldehyde = cyclohexanecarbaldehyde.
Why the other options are incorrect
Option (1) Benzaldehyde — Incorrect. This is \( \ce{C6H5CHO} \), with the –CHO group on an aromatic benzene ring (IUPAC name benzenecarbaldehyde); the ring here is saturated.
Option (2) Cyclohexanealdehyde — Incorrect. “Aldehyde” is not an IUPAC suffix; the ring compound takes the suffix carbaldehyde.
Option (3) Cyclohexanal — Incorrect. The ending –al means the CHO carbon is part of the parent chain; a ring carbon cannot be a CHO carbon, so this name describes no compound.
NCERT (2026-27 edition):
IUPAC Names
