The IUPAC name of `CH_3-underset(CH_3)underset(|)overset(CH_3)overset(|)C-CH=CH_2`
is -

Options

A. 2,2 - Dimethyl -3- butane
B. 2,2 - Dimethyl -4- pentene
C. 3,3 - Dimethyl - 1- butene
D. 1 - Hexene

Answer

To determine the IUPAC name of the compound `CH3-CH(CH3)-C(CH3)=CH2`, we will follow these steps:

### Step 1: Identify the Longest Carbon Chain
The first step is to identify the longest continuous carbon chain that includes the double bond. In this case, the longest chain consists of four carbon atoms.

### Step 2: Number the Carbon Chain
Next, we need to number the carbon chain. The numbering should be done in such a way that the double bond receives the lowest possible number.

- If we number from left to right:
- C1: CH2 (double bond here)
- C2: CH (with a methyl group)
- C3: C (with a methyl group)
- C4: CH3

This gives us the numbering: 1, 2, 3, 4.

### Step 3: Identify the Position of the Double Bond
The double bond is located between C1 and C2, so we denote it as "but-1-ene" since there are four carbons in the chain and the double bond starts at the first carbon.

### Step 4: Identify and Name the Substituents
We have two methyl groups attached to the second carbon (C2) of the chain. Therefore, we denote these substituents as "dimethyl".

### Step 5: Combine the Information
Combining all the information, we find that the compound has:
- A four-carbon chain (but-)
- A double bond at the first position (1-ene)
- Two methyl groups at the third position (3,3-dimethyl)

Thus, the complete IUPAC name is **3,3-dimethylbut-1-ene**.

### Final Answer
The IUPAC name of the compound `CH3-CH(CH3)-C(CH3)=CH2` is **3,3-dimethylbut-1-ene**.

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