IUPAC Naming: Troubleshooting Mistakes

[Manh]

Homework Statement

Give the IUPAC name for the following compound.

Homework Equations

The Attempt at a Solution

However, the 4 and 7 were incorrect in the blanks. I'm not sure what went wrong.

 

[Dr Transport]

I think it is 3-ethyl, 6-isopropyl nonane

3 & 6 are smaller than 4 & 7

 

[Bystander]

3-ethyl

"3-methyl" you mean?

 

[Dr Transport]

yes... methyl as opposed to ethyl...

 

[Manh]

I think it is 3-ethyl, 6-isopropyl nonane

I wonder if you are counting # of C in this order like this: