A five C-atom hydrocarbon is formed by the reduction of a chloroderivative (A) of an alkane with Zn-Cu couple. (A) (A) is dissolved in dry ether and then treated with metallic sodium to give 2, 2, 5, 5-tetramethyl hexane. The IUPAC name of compound (A) is:

Options

A. Neopentyl chloride
B. 1–chloro-2,2-dimethyl propane
C. 1-chloro-3-methyl butane
D. 2-chloro-3-methylbutane

Answer

To solve the problem, we need to determine the IUPAC name of compound (A), which is a chloroderivative of an alkane that leads to the formation of 2,2,5,5-tetramethylhexane upon treatment with metallic sodium in dry ether.

### Step-by-Step Solution:

1. **Identify the Product**:
The product formed is 2,2,5,5-tetramethylhexane. This compound has a total of 8 carbon atoms (6 from the hexane chain and 2 from the methyl groups).

2. **Understand the Reaction**:
The reduction of a chloroderivative (A) with Zn-Cu couple suggests that (A) is a haloalkane. The Wurtz reaction is also mentioned, which indicates that (A) must be a symmetrical compound that can combine to form the final product.

3. **Determine the Structure of (A)**:
Since the final product has 8 carbon atoms, and we need to reverse the Wurtz reaction, we can deduce that (A) must be a chlorinated derivative that can yield two identical alkyl groups upon reaction with sodium.

4. **Construct the Chloroderivative**:
The structure of 2,2,5,5-tetramethylhexane can be broken down:
- The longest carbon chain is hexane (6 carbons).
- There are two methyl groups on the second carbon and two methyl groups on the fifth carbon.

Thus, if we consider the symmetrical nature of the Wurtz reaction, we can infer that the chloroderivative (A) must be 1-chloro-2,2-dimethylpropane.

5. **Write the IUPAC Name of (A)**:
The IUPAC name for the compound we constructed is 1-chloro-2,2-dimethylpropane.

### Final Answer:
The IUPAC name of compound (A) is **1-chloro-2,2-dimethylpropane**.