IUPAC name of neopentyl group is :

Options

A. 2,2-dimethylbutyl
B. 2,2-dimethylproplyl
C. 1,1-dimethylbutyl
D. 1,1-dimethylpropyl

Answer

To determine the IUPAC name of the neopentyl group, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Structure of Neopentyl Group**:
The neopentyl group has the following structure:
\[ \text{CH}_3 - \text{C}(\text{CH}_3)_2 - \text{CH}_2^- \]
This indicates that it consists of a central carbon atom bonded to two methyl groups and one methylene group with a vacant valency.

2. **Count the Carbon Atoms**:
The total number of carbon atoms in the neopentyl group is five (1 central carbon + 2 from methyl groups + 1 from methylene).

3. **Determine the Longest Carbon Chain**:
The longest continuous carbon chain in the structure is three carbons long, which corresponds to a propyl group.

4. **Identify the Substituents**:
There are two methyl groups attached to the second carbon of the propyl chain.

5. **Number the Carbon Chain**:
Number the carbon chain starting from the end closest to the substituents:
- The carbon chain can be numbered as follows:
- 1: CH2 (the end carbon)
- 2: CH (the central carbon with substituents)
- 3: CH3 (the other end carbon)

6. **Write the Name of the Compound**:
Since there are two methyl groups on the second carbon, we denote this as "2,2-dimethyl". The base name for a three-carbon chain is "propyl".

7. **Combine the Parts**:
Therefore, the complete IUPAC name for the neopentyl group is:
\[ \text{2,2-dimethylpropyl} \]

### Final Answer:
The IUPAC name of the neopentyl group is **2,2-dimethylpropyl**.

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