[Enzo]

Hey folks

We're covering hydrocarbon naming in one of my engineering units, but the lecturer was amazing enough to not have any notes on it.

I have a quick question to ask: I see one hydrocarbon chain named "2,2-dimethylbutane"

I understand the "2,2" part (because they're connecting to the second carbon), also the "methyl" (as there's one carbon atom in each substituent branch", and butane because the longest carbon chain is 4 carbons long.... But where does the "di" come in from?

Thanks for any help you can offer

[Astrokel]

hey Enzo,

the di is because there are 2 methyl groups on the 2nd carbon atom of the main chain. Similarly if there is 3 methyl group then it would be called trimethyl.

[Enzo]

Awesome..That's what I initially thought. The only problem im having is that there's also another example "2,3-dimethylbutane". So what you're saying is that it doesn't really matter where the "methyl" is located on the chain..if there's 2 of them, it's going to have the prefix "di"?

Thanks so much for your help, mate.

Do you know of any good sites that really explain this topic well?

[macman104]

http://www.cem.msu.edu/~reusch/VirtualText/nomen1.htm