Butane can be prepared from ethyl chloride using the following synthesis
`CH_(3)CH_(2)Cloverset((i)Li)underset((i)Cu l)rarr(CH_(3)CH_(2))_(2)LiCu overset(CH_(3)CH_(2)Cl)rarr CH_(3)CH_(2)CH_(2)CH_(3)`
The reaction is

Options

A. Wurtz reaction
B. Kolbe's electrolytic method
C. Sandmayer's reaction
D. Corey - House synthesis

Answer

To solve the question regarding the preparation of butane from ethyl chloride, we can break down the process step by step.

### Step-by-Step Solution

1. **Identify the Starting Material**:
The starting material is ethyl chloride, which is represented as CH₃CH₂Cl.

**Hint**: Always start by identifying the reactants in the given synthesis.

2. **Reaction with Lithium and Copper Iodide**:
Ethyl chloride (CH₃CH₂Cl) is treated with lithium (Li) and copper iodide (CuI). This reaction forms a compound known as diethyl copper lithium, represented as (CH₃CH₂)₂LiCu.

**Hint**: Recognize that lithium and copper iodide are used to generate a dialkylcopper reagent, which is crucial in this synthesis.

3. **Formation of Diethyl Copper Lithium**:
The reaction can be summarized as:
\[ \text{CH}_3\text{CH}_2\text{Cl} + \text{Li} + \text{CuI} \rightarrow \text{(CH}_3\text{CH}_2)_2\text{LiCu} \]

**Hint**: This step involves the formation of a new organometallic compound, which is key to the next step.

4. **Reaction with Another Ethyl Chloride**:
The diethyl copper lithium compound then reacts with another molecule of ethyl chloride (CH₃CH₂Cl). This reaction leads to the formation of butane (CH₃CH₂CH₂CH₃).

**Hint**: The reaction here is a coupling reaction where two ethyl groups are combined to form butane.

5. **Final Reaction Equation**:
The overall reaction can be summarized as:
\[ \text{(CH}_3\text{CH}_2)_2\text{LiCu} + \text{CH}_3\text{CH}_2\text{Cl} \rightarrow \text{CH}_3\text{CH}_2\text{CH}_2\text{CH}_3 + \text{LiCl} + \text{CuI} \]

**Hint**: Always ensure to balance the reaction and identify byproducts, which in this case are lithium chloride and copper iodide.

6. **Identify the Type of Reaction**:
This entire process is known as the **Coray-House synthesis**, which is a method for preparing alkanes from alkyl halides.

**Hint**: Recognize the significance of the Coray-House synthesis in organic chemistry, especially for synthesizing alkanes.

### Conclusion
The reaction described in the question is known as **Coray-House synthesis**.

**Final Answer**: Coray-House synthesis.