Question

$C{H}_3-C{H}_2-\underset{C{H}_3}{\underset{|}{C}}=CH-C{H}_2-\stackrel{C{H}_3}{\stackrel{|}{C}H}-C{H}_2-C{H}_3$

What is the IUPAC name of the following compound?

• A. 3, 6-Dimethyl-3-octene
• B. 3, 6-Dimethyl-3-octene
• C. 2-Ethyl-5-methyl-2-heptene
• D. None of the above

Answer 1

The correct option is A

3, 6-Dimethyl-3-octene

If you can get the pareny chain right, you will get the answer.

Parent chain is
$\stackrel{1}{C}{H}_3-\stackrel{2}{C}{H}_2-\stackrel{3}{\underset{C{H}_3}{\underset{|}{C}}}=\stackrel{4}{C}H-\stackrel{5}{C}{H}_2-\stackrel{C{H}_3}{\stackrel{6|}{C}H}-\stackrel{7}{C}{H}_2-\stackrel{8}{C}{H}_3$

Word root$\Rightarrow$ but

Double bond$\Rightarrow$suffix$\Rightarrow$ene

Two methyl groups at $C_3$and$C_5\Rightarrow$3, 6-dimethyl

Therefore,

(a) 3, 6-Dimethyl-3-octene