Question

Draw 2-ethyl-5-sec-butylheptane and what is the correct iupac name?

Answer 1

The correct IUPAC name is 4-ethyl-3,7-dimethylnonane.

Explanation:

The structure of 2-ethyl-5-sec-butylheptane is

The 7-carbon chain is the horizontal zig-zag line.

The ethyl group is on `"C-2"`, and the sec-butyl group is on `"C-5"`.

But the longest continuous chain is the 9-carbon chain that runs from the top to the lower right.

We start numbering from the lower right, because that end is closer to more substituents — it gives us lower numbers.

There are methyl groups on `"C-3"` and on `"C-7"`, and an ethyl group on `"C-4"`.

The IUPAC name is therefore 4-ethyl-3,7-dimethylnonane.