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 identify the IUPAC name of the chloroderivative (A) of an alkane that leads to the formation of 2,2,5,5-tetramethylhexane upon reduction with a zinc-copper couple and subsequent treatment with metallic sodium.

### Step-by-Step Solution:

1. **Understanding the Product**:
The product formed is 2,2,5,5-tetramethylhexane. This indicates that the hydrocarbon has a total of 5 carbon atoms in its structure. The structure can be represented as follows:
- The main chain is hexane (6 carbon atoms), but since we are looking for a 5 carbon atom hydrocarbon, we need to consider that the branching will lead to a reduction in the effective carbon count.

2. **Identifying the Structure**:
The structure of 2,2,5,5-tetramethylhexane can be drawn out:
- The main chain is hexane (C6), but due to the branching (two methyl groups at C2 and two at C5), we can deduce that the original compound (A) must have been a chlorinated derivative that allows for this branching.

3. **Considering the Reaction**:
The reaction described involves the reduction of a chlorinated compound (A) using Zn-Cu couple, which typically indicates that we are dealing with a compound that can undergo a coupling reaction with sodium metal in dry ether.

4. **Determining the Chloroderivative (A)**:
To form 2,2,5,5-tetramethylhexane, the chloroderivative (A) must have the following structure:
- The chlorinated compound must be 1-chloro-2,2-dimethylpropane (C5H11Cl). This compound has a chlorine atom on the first carbon and two methyl groups on the second carbon, which allows for the formation of the desired product upon reduction.

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

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