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

1 Answer
Aug 25, 2015

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


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.