Which of the following reaction is/are correct?

Options

A. a.
B. b.
C. c.
D. d.

Explanation

To determine which of the reactions are correct, we will analyze each reaction step by step based on the information provided in the video transcript.

### Step 1: Identify the Reactions
The question presents multiple reactions, and we need to evaluate each one. The first two reactions involve the same reagents, which are Raney nickel and hydrogen.

### Step 2: Analyze the First Two Reactions
- **Reagents Used**: Raney nickel and hydrogen.
- **Type of Reaction**: This is a reduction reaction.
- **Mechanism**: The carbonyl group (C=O) in the ketone (pentanone) is reduced to a CH2 group, forming a hydrocarbon (cyclopentane).
- **Conclusion**: The first reaction is correct.

### Step 3: Analyze the Second Reaction
- **Reagents Used**: Same as the first reaction (Raney nickel and hydrogen).
- **Substrate**: Benzaldehyde (C6H5CHO).
- **Mechanism**: The carbonyl group in benzaldehyde is reduced to a CH2 group, forming toluene (C6H5CH3).
- **Conclusion**: The second reaction is also correct.

### Step 4: Analyze the Third Reaction
- **Reagents Used**: Peroxo acid (peracid).
- **Substrate**: Ketone (R-C(=O)-R').
- **Mechanism**: The reaction with peroxo acid leads to the formation of an ester. The oxygen from the peracid is added to the more electron-rich alkyl group.
- **Conclusion**: The third reaction is correct.

### Step 5: Analyze the Fourth Reaction
- **Reagents Used**: Peroxo acid (peracid).
- **Substrate**: Toluene (C6H5CH3) and phenyl ring (C6H5).
- **Mechanism**: The reaction with peracid will add oxygen to the more electron-rich group, which in this case is toluene due to the +I effect of the methyl group. Hence, oxygen will be added to the toluene side.
- **Conclusion**: The fourth reaction is also correct.

### Final Conclusion
After analyzing all the reactions:
- **Option A**: Correct
- **Option B**: Correct
- **Option C**: Correct
- **Option D**: Correct

Thus, all of the reactions presented in the question are correct.

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