What is the name of this hydrocarbon?

Question

http://i34.tinypic.com/11htnyg.jpg

Answer 1

It's either 2,2,4-trimethyl-4-pentene or 2,4,4-trimethyl-1-pentene...

hope this helps!!!

Answer 2

The principal functional group is the alkene (the carbon carbon double bond), therefore we select the longest chain which contains the double bond. We can pick the chain going straight across (length 5); hence, we start numbering from the right end, since it gives the double bond a lower number. Then, there are three methyl substitutents at positions 2, 4, 4. The name is 2,4,4-trimethylpent-1-ene.