Question

What is the IUPAC name of Mesityl oxide?

• A. 4-methylpent-3-en-2-one
• B. 2,4,6-Trimethylphenylacetone
• C. 2,4,6-Trimethyl-3-penten-2-one
• D. 2,4,6-Trimethyl-3-hexen-2-one

Hint:

When naming compounds, always identify the parent chain and use the lowest possible locants for substituents and functional groups.

Answer 1

The Correct Option is C

Step 1: Understanding Mesityl oxide.
Mesityl oxide is an organic compound with the molecular formula \(C_9H_{12}O\). It is a ketone that consists of a 2,4,6-trimethylphenyl group attached to a pentenone structure.
Step 2: IUPAC Nomenclature.
In IUPAC nomenclature, the compound is named based on the parent chain (a five-carbon chain) and the position of the functional groups. The numbering is done in such a way that the lowest possible numbers are given to the substituents and functional groups.
Step 3: Analysis of the options.
\begin{itemize} \item (A) 4-methylpent-3-en-2-one: Incorrect. This structure does not match the Mesityl oxide structure. \item (B) 2,4,6-Trimethylphenylacetone: Incorrect. This name refers to a different structure than Mesityl oxide. \item (C) 2,4,6-Trimethyl-3-penten-2-one: Correct. This is the correct IUPAC name for Mesityl oxide. \item (D) 2,4,6-Trimethyl-3-hexen-2-one: Incorrect. The parent chain is five carbons, not six. \end{itemize}
Step 4: Conclusion.
Based on the analysis, the correct IUPAC name for Mesityl oxide is 2,4,6-Trimethyl-3-penten-2-one.
Final Answer: 2,4,6-Trimethyl-3-penten-2-one.