posted by Lena .
For methyl-2-butene how do I know what the methyl group is coming off of?
A great question. And an equally great answer when you think about it. It MUST come off the 2 carbon BECAUSE if it came off the 1 carbon, it wouldn't be butene anymore would it? If the methyl group came off the 1 carbon, the chain would be 5 C atoms long and would be named 2-pentene. Right? So the first 2 in 2-methyl-2-butene isn't needed. Isn't chemistry fun?
Oh, I see it now. Thanks so much :)