Question

What is the IUPAC name of (CH3)3CCH2COOH?

(a) Hexanoic acid

(b) 2,2,2-Trimethylpropanoic acid

(c) 3,3-Dimethylbutanoic acid

(d) 4-Methylpentanoic acid

The question was asked during an interview.

I'm obligated to ask this question of Nomenclature and Structure of Carboxyl Groups topic in division Aldehydes, Ketones and Carboxylic Acids of Chemistry – Class 12

Answer 1

Right option is (c) 3,3-Dimethylbutanoic acid

Best explanation: The longest parent carbon chain consists of 4 carbon atoms including the carboxyl carbon and one methyl group attached to the tertiary carbon. The other two methyl groups act as substituents on the carbon, which is now the third carbon.