The hyrocarbon with seven carbon atoms containing a neopentyl and a vinyl group is :

Options

A. 4,4-dimethylpentene
B. 2,2-dimenthyl-3-pentene
C. Isopropyl-2-butene
D. 2,2-dimethyl-4-pentene

Answer

To determine the hydrocarbon with seven carbon atoms containing a neopentyl and a vinyl group, we can follow these steps:

### Step 1: Understand the Groups
- **Neopentyl Group**: The neopentyl group (C5H11) can be represented as:
```
CH3
|
CH3 - C - CH2 -
|
CH3
```
This structure shows that neopentyl has a central carbon atom bonded to four other carbon atoms.

- **Vinyl Group**: The vinyl group (C2H3) is represented as:
```
CH2 = CH
```

### Step 2: Combine the Groups
- To form a hydrocarbon with both groups, we need to connect the neopentyl group to the vinyl group while ensuring the total number of carbon atoms is seven.
- The structure can be visualized as:
```
CH3
|
CH3 - C - CH2 - CH = CH2
|
CH3
```
This gives us a total of 7 carbon atoms.

### Step 3: Number the Carbon Atoms
- We will number the carbon atoms starting from the end of the chain where the double bond is located, as functional groups take precedence in numbering.
- The numbering would look like this:
```
1 2 3 4 5 6 7
CH2 = CH - CH2 - C - CH3
|
CH3
```

### Step 4: Identify Substituents
- At carbon 4, there are two methyl (CH3) groups attached. This is indicated as "4,4-dimethyl".
- The main chain is a pentene because of the double bond starting at carbon 1.

### Step 5: Write the IUPAC Name
- The IUPAC name of the compound is derived from the longest carbon chain, which is pentene, and includes the substituents:
- The name will be "4,4-dimethylpent-1-ene".

### Final Answer
Thus, the hydrocarbon with seven carbon atoms containing a neopentyl and a vinyl group is **4,4-dimethylpent-1-ene**.

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