During reduction of aldehydes with hydrazine and potassium hydroxide, the first is formation of

Options

A. `R-C-=N`
B. `R-CO-NH_(2)`
C. `R-CH=NH`
D. `R-CH=N-NH_(2)`

Explanation

To solve the question regarding the reduction of aldehydes with hydrazine and potassium hydroxide, we need to understand the process and identify the intermediate formed during the reaction. Here’s a step-by-step breakdown:

### Step 1: Understand the Reactants
The reactants in this reaction are:
- Aldehyde (RCHO)
- Hydrazine (N2H4)
- Potassium hydroxide (KOH)

### Step 2: Identify the Reaction Type
This reaction is a reduction process, specifically known as the Wolff-Kishner reduction. In this reaction, the carbonyl group (C=O) of the aldehyde is reduced to a methylene group (–CH2–).

### Step 3: Formation of the Intermediate
When an aldehyde reacts with hydrazine, the first step involves the formation of a hydrazone. This occurs through the nucleophilic attack of hydrazine on the carbonyl carbon of the aldehyde, followed by the elimination of water. The reaction can be summarized as follows:

1. Aldehyde (RCHO) + Hydrazine (N2H4) → Hydrazone (RCH=N-NH2) + H2O

The structure of the hydrazone can be represented as:
- RCH=N-NH2

### Step 4: Final Product Formation
After the formation of the hydrazone, the next step involves the reduction of the hydrazone to an alkane. This is facilitated by the presence of potassium hydroxide and heat, leading to the elimination of nitrogen gas (N2) and the formation of the final product, which is an alkane (RCH2R').

### Conclusion
The intermediate formed during the reduction of aldehydes with hydrazine and potassium hydroxide is the hydrazone, represented as:
- RCH=N-NH2

### Final Answer
The correct answer to the question is that the first intermediate formed is a hydrazone (RCH=N-NH2).

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