Which of the following is not formed by the ozonolysis of (o-xylene)

Options

A. Glyoxal
B. Ethyl glyoxal
C. Dimethyl glyoxal
D. Methyl glyoxal

Answer

To solve the question regarding the ozonolysis of ortho-xylene and identify which product is not formed, we can follow these steps:

### Step 1: Understand Ozonolysis
Ozonolysis is a reaction where ozone (O₃) reacts with alkenes to form carbonyl compounds (aldehydes or ketones). In the case of xylene, which has two methyl groups attached to the benzene ring, we need to analyze how ozonolysis will affect its structure.

### Step 2: Identify the Structure of Ortho-Xylene
Ortho-xylene (1,2-dimethylbenzene) has two methyl groups attached to adjacent carbon atoms on the benzene ring. The structure can be represented as follows:

```
CH3
|
C6H4-CH3
```

### Step 3: Analyze the Ozonolysis Products
When ozonolysis occurs, the double bonds in the structure will react with ozone. The products formed from the ozonolysis of ortho-xylene can include:

1. **Glyoxal (C₂H₂O₂)**: Formed from the cleavage of the double bond.
2. **Dimethylglyoxal (C₄H₄O₂)**: Another possible product from the reaction.
3. **Methylglyoxal (C₃H₄O₂)**: Also formed during the ozonolysis process.

### Step 4: Identify the Product Not Formed
From the analysis of the products, we can summarize:
- Glyoxal is formed.
- Dimethylglyoxal is formed.
- Methylglyoxal is formed.
- Ethylglyoxal (C₄H₈O₂) is not formed during this reaction.

### Conclusion
The product that is **not formed** by the ozonolysis of ortho-xylene is **ethylglyoxal**.

### Final Answer
**Ethylglyoxal is not formed by the ozonolysis of ortho-xylene.**

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