Question

Which of the following is the correct IUPAC name?

Options

• 3-Ethyl-4, 4-dimethylheptane

• 4, 4-Dimethyl-3-ethylheptane

• 5-Ethyl-4, 4-dimethylheptane

• 4, 4-Bis(methyl)-3-ethylheptane

Answer 1

4, 4-Dimethyl-3-ethylheptane

Explanation:

While writing IUPAC name, the alkyl groups are written in alphabetical order. Thus lower locant 3 is assigned to ethyl. Prefix, di, tri, and tetra are not included in alphabetical order.

\[\begin{array}{cc}
\phantom{....}\ce{CH3}\\
\phantom{.}|\\
\ce{CH3 - CH2 - CH2 - C - CH - CH2 - CH3}\\
\phantom{......}|\phantom{....}|\phantom{.}\\
\phantom{........}\ce{CH3}\phantom{.}\ce{CH3}\phantom{}
\end{array}\]