A reagent that is required to convert methyl cyanide into acetaldehyde is ________.

Options

A. ethyl magnesium chloride
B. methyl magnesium chloride
C. acetyl chloride
D. `SnCl_(2)//HCl`

Answer

To convert methyl cyanide (also known as acetonitrile) into acetaldehyde, we need to follow a specific chemical reaction. Here’s the step-by-step solution:

### Step 1: Identify the Reactant and Product
- **Reactant**: Methyl cyanide (CH₃CN)
- **Product**: Acetaldehyde (CH₃CHO)

### Step 2: Understand the Required Reaction
To convert methyl cyanide to acetaldehyde, we can use a reagent that facilitates the transformation of the nitrile group (-CN) into an aldehyde group (-CHO).

### Step 3: Select the Appropriate Reagent
The reagent that can achieve this transformation is **SnCl₂ (tin(II) chloride) in the presence of HCl**. This combination is known for its ability to convert nitriles into aldehydes.

### Step 4: Mechanism of the Reaction
1. **Formation of an Imine**: The SnCl₂ in HCl first reacts with the nitrile to form an imine intermediate.
2. **Hydrolysis**: Upon hydrolysis, the imine is converted into the corresponding aldehyde, which in this case is acetaldehyde.

### Step 5: Conclusion
Thus, the reagent required to convert methyl cyanide into acetaldehyde is **SnCl₂ in the presence of HCl**.

### Final Answer
The reagent that is required to convert methyl cyanide into acetaldehyde is **SnCl₂ in the presence of HCl**.

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