The suitable reagent to convert `CH_(3)-CH=CH-CHO` into `CH_(3)-CH_(2)-CH_(2)-CH_(2)-OH`

Options

A. `NaBH_(4)`
B. `LiAIH_(4)`
C. `Zn-Hg//HCI`
D. `H_(2)//Pd`

Explanation

To convert the compound `CH₃-CH=CH-CHO` (which is an allylic aldehyde) into `CH₃-CH₂-CH₂-CH₂OH` (a primary alcohol), we need to perform a reduction that targets both the double bond and the aldehyde functional group. Here’s how we can approach this step by step:

### Step 1: Identify the Functional Groups
The starting compound `CH₃-CH=CH-CHO` contains:
- An aldehyde group (-CHO)
- A carbon-carbon double bond (C=C)

The target compound `CH₃-CH₂-CH₂-CH₂OH` is a primary alcohol, which means we need to reduce both the aldehyde and the double bond.

### Step 2: Choose the Suitable Reagent
To achieve the desired transformation, we need a reagent that can reduce both the double bond and the aldehyde.

1. **NaBH₄ (Sodium Borohydride)**: This reagent is selective for aldehydes and ketones but does not reduce alkenes (double bonds). So, it is not suitable.

2. **LiAlH₄ (Lithium Aluminium Hydride)**: This is a strong reducing agent that can reduce aldehydes and ketones to alcohols, but it does not reduce double bonds. Therefore, it is also not suitable.

3. **Zn/HCl (Clemenson Reduction)**: This method is used to reduce aldehydes to alkanes but does not affect double bonds. Hence, it is not suitable for our purpose.

4. **H₂/Pd (Hydrogenation)**: This reagent can reduce both alkenes and aldehydes. Under the right conditions, it can convert the double bond to a single bond and the aldehyde to an alcohol. This makes it the most suitable reagent for our reaction.

### Step 3: Perform the Reaction
Using H₂ in the presence of a palladium catalyst (Pd), we can perform the following transformations:
- The double bond (C=C) will be hydrogenated to a single bond (C-C).
- The aldehyde group (-CHO) will be reduced to a primary alcohol (-CH₂OH).

### Final Answer
Thus, the suitable reagent to convert `CH₃-CH=CH-CHO` into `CH₃-CH₂-CH₂-CH₂OH` is **H₂/Pd**.

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