Question

The IUPAC name of the following componds is

• A. 1-Cyclopentyl-3, 4-dimethylbutene
• B. 1-Cyclopentyl-3-methylpent-1-ene
• C. (3-Methyl-1-pentenyl) cyclopentane
• D. None of these

Answer 1

The correct option is B

1-Cyclopentyl-3-methylpent-1-ene

What should be our first step to solve this problem?

$\to$ The first step is finding out the parent chain.

Here, the parent chain will be the open chain.

Because it has a double bond in it

$\to$ Now give the numbering to the parent chain.

We started numbering from left hand side, so that double bond takes least number.

Now,

Parent chain $\to$ 5 carbons $\Rightarrow$ Word root $\to$ pent

Double bound $\Rightarrow$

Primary suffix $\to$ ene

$\Rightarrow$ pent-1-ene

Now, about the substitutes,

There is cyclopentyl group at $C_1$ and methyl group at $C_3$

Therefore,

1-Cyclopentyl-3-methylpent-1-ene