The IUPAC name of the compound `CH_(2)=CH-CH(CH_(3))_(2)` is

Options

A. 1, 1 - dimethyl 1 - 2 - butene
B. 3 - methyl -1 - butene
C. 2 - vinyl propane
D. None of these

Answer

To determine the IUPAC name of the compound `CH2=CH-CH(CH3)2`, we can follow these steps:

### Step 1: Identify the Structure
The compound can be represented as:
- CH2=CH-CH(CH3)2

This indicates that we have:
- A double bond between the first two carbon atoms (C1 and C2).
- A carbon chain where the third carbon (C3) has two methyl (CH3) groups attached to it.

### Step 2: Determine the Longest Carbon Chain
The longest continuous carbon chain contains 4 carbon atoms:
1. C1: CH2
2. C2: CH
3. C3: CH (with two methyl groups attached)
4. C4: CH3

### Step 3: Number the Carbon Chain
When numbering the carbon chain, we start from the end nearest to the double bond to give the double bond the lowest possible number:
- C1: CH2 (1)
- C2: CH (2)
- C3: C(CH3)2 (3)
- C4: CH3 (4)

### Step 4: Identify the Functional Group
The principal functional group here is the alkene (due to the double bond). Since the double bond starts at C1, we will indicate its position in the name.

### Step 5: Identify Substituents
There is one substituent:
- A methyl group (CH3) on C3. Since there are two methyl groups, we denote this as "dimethyl".

### Step 6: Construct the IUPAC Name
Putting it all together:
- The longest chain is butane (4 carbons).
- The double bond is at position 1 (but-1-ene).
- There are two methyl groups at position 3 (3,3-dimethyl).

Thus, the IUPAC name of the compound is:
**3,3-Dimethylbut-1-ene**

### Final Answer
The IUPAC name of the compound `CH2=CH-CH(CH3)2` is **3,3-Dimethylbut-1-ene**.

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