For obtaining butan-2-one from acetyl chloride, which of the following reagent can be employed?

Options

A. Grignard reagent
B. reaction with HI
C. `H_(2)//Pd-BaSO_(4)`
D. reaction with `(C_(2)H_(5))_(2)Cd` in the presence of dry ether.

Explanation

To obtain butan-2-one from acetyl chloride, we can use diethylcadmium as the reagent. Here’s a step-by-step breakdown of the process:

### Step 1: Identify the Reactant and Product
- **Reactant**: Acetyl chloride (CH3C(=O)Cl)
- **Product**: Butan-2-one (CH3C(=O)CH2CH3)

### Step 2: Write the Structure of Acetyl Chloride
- The structure of acetyl chloride is:
```
O
||
CH3-C-Cl
```

### Step 3: Identify the Reagent
- The reagent we will use is diethylcadmium (C2H5)2Cd. This reagent contains two ethyl groups which will be used to form the desired product.

### Step 4: Reaction Mechanism
- When acetyl chloride reacts with diethylcadmium in the presence of dry ether, the ethyl groups from diethylcadmium will replace the chlorine atom in acetyl chloride.
- The reaction can be represented as:
```
CH3C(=O)Cl + (C2H5)2Cd → CH3C(=O)C2H5 + CdCl2
```

### Step 5: Product Formation
- The product formed from this reaction is butan-2-one (CH3C(=O)CH2CH3).
- The structure of butan-2-one is:
```
O
||
CH3-C-CH2-CH3
```

### Conclusion
- The reagent used to obtain butan-2-one from acetyl chloride is **diethylcadmium**.