Chemistry - Nomenclature Question with Solution | TestHub

Explain the question:

Determine the correct IUPAC name for the given cyclic compound.

Concept :

Priority: Aldehyde > Ketone > Halogen.

Solution :

To name the compound, we follow the IUPAC rules for functional group priority:

1. Identify Principal Group: The aldehyde group (–CHO ) has a higher priority than the ketone (=O) and the bromine substituent. Therefore, the parent name is cyclohexanecarbaldehyde, and the carbon attached to the -CHO group is assigned position

2. Numbering the Ring: We number the ring to give the substituents the lowest possible locants.

Starting from C₁ , we move clockwise or counter-clockwise. Numbering towards the ketone gives locants 3 and 5.

3. Alphabetical Order: The substituents are "bromo" and "oxo" (ketone as a prefix). Alphabetically, Bromo comes before Oxo. To give the lowest locant to the first alphabetical group, we number such that Bromo is at 3 and Oxo is at 5 .

Position 1: –CHO (carbaldehyde)

Position 3: – Br (bromo)

Position 5: = O (oxo)

Combining these, the name is 3-Bromo-5-oxocyclohexanecarbaldehyde. Final Answer  option (C)