# Question #3da98

Jul 2, 2016

Here's how to generate the IUPAC name.

#### Explanation:

The prime rule is that you choose the longest continuous chain that includes both the carboxylic acid and the alkene double bond.

Start from the $\text{COOH}$ and count to the left hand end. That gives you a 5-carbon chain:

$\text{C-C=C-C-COOH}$

The base name for this chain becomes "pentenoic acid".

The carboxyl carbon is number 1, so the double bond is between carbons 3 and 4.

The name becomes "pent-3-enoic acid", with the "3" coming as close as possible before the "en".

Now, we have two methyl groups on carbon 2:

$\text{CH"_3"CH=CHC"("CH"_3)_2"COOH}$

The IUPAC name is 2,2-dimethylpent-3-enoic acid.