In order to prepare acetone from acetyl chloride in one step, which of the following reagents will be best ?

Options

A. Reduction with `H_(2)//Pd-BaSO_(4)`
B. Reduction with HI
C. Grignard's reagent
D. Dimethyl cadmium

Explanation

To prepare acetone from acetyl chloride in one step, we need to identify the best reagent from the options provided. The process involves a reaction where acetyl chloride (CH3COCl) is transformed into acetone (CH3C(=O)CH3).

### Step-by-Step Solution:

1. **Identify the Reactants**: The starting material is acetyl chloride (CH3COCl). We need to convert this into acetone (CH3C(=O)CH3).

2. **Determine the Required Reaction**: Acetone can be synthesized from acetyl chloride through a nucleophilic addition reaction. In this case, we need a reagent that can effectively add to the carbonyl carbon of acetyl chloride.

3. **Choose the Reagent**: Among the potential reagents, dimethyl cadmium (C2H6Cd) is a suitable choice. Dimethyl cadmium acts as a nucleophile and can react with acetyl chloride.

4. **Reaction Mechanism**:
- When dimethyl cadmium (C2H6Cd) reacts with acetyl chloride, it donates a methyl group to the carbonyl carbon of acetyl chloride.
- The reaction can be represented as:
\[ \text{CH}_3\text{COCl} + \text{C}_2\text{H}_6\text{Cd} \rightarrow \text{CH}_3\text{C(=O)CH}_3 + \text{CdCl}_2 \]
- This results in the formation of acetone (CH3C(=O)CH3) and cadmium chloride (CdCl2).

5. **Conclusion**: Therefore, the best reagent to prepare acetone from acetyl chloride in one step is dimethyl cadmium.

### Final Answer:
The correct option for this question is **Dimethyl Cadmium (Option D)**.

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