Question

Identify the correct common name for the following compound.

(a) 3-Methylcyclohexanecarbaldehyde

(b) 3-Methylbenzecarbaldehyde

(c) 3-Methylbenzaldehyde

(d) γ-Methylcyclohexanecarbaldehyde

I had been asked this question during an internship interview.

Enquiry is from Nomenclature and Structure of Carbonyl Groups in section Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

Answer 1

Correct choice is (d) γ-Methylcyclohexanecarbaldehyde

Best explanation: This compound is a cyclic aldehyde where numbering starts from the carbon to which the CHO group is attached. So, the carbon to which methyl group is attached is the third carbon. In the common system, this carbon is known as the gamma carbon.