Write down the products of ozonolysis of 1, 2-dimethylbenzene (o-xylene). How does the result support Kekulé structure for benzene?

Explanation

To solve the question regarding the ozonolysis of 1,2-dimethylbenzene (o-xylene) and how it supports the Kekulé structure for benzene, we can follow these steps:

### Step 1: Understand Ozonolysis
Ozonolysis is a reaction where ozone (O₃) is used to cleave double bonds in alkenes and some aromatic compounds. In the case of aromatic compounds like o-xylene, ozonolysis leads to the formation of carbonyl compounds.

### Step 2: Structure of 1,2-Dimethylbenzene (o-Xylene)
1,2-Dimethylbenzene, commonly known as o-xylene, has the following structure:
```
CH3
|
C6H4 - C - CH3
```
This structure can be represented as a benzene ring with two methyl groups attached to adjacent carbon atoms (ortho position).

### Step 3: Perform Ozonolysis
When o-xylene undergoes ozonolysis, ozone reacts with the double bonds in the aromatic ring. The reaction typically involves the formation of ozonides, which are then hydrolyzed (usually with zinc and water) to yield carbonyl compounds.

The ozonolysis of o-xylene will yield:
- Acetophenone (C6H5C(O)CH3)
- Benzaldehyde (C6H5CHO)

The overall reaction can be summarized as:
```
C6H4(CH3)2 + O3 → C6H5C(O)CH3 + C6H5CHO
```

### Step 4: Analyze the Products
The products of ozonolysis indicate that the reaction cleaves the aromatic ring and forms carbonyl compounds. The presence of these specific products suggests that the structure of benzene can be represented by the Kekulé model, which includes alternating single and double bonds.

### Step 5: Relate to Kekulé Structure
Kekulé proposed that benzene has a resonance structure, which means it can be represented in different forms. The fact that ozonolysis of o-xylene leads to specific carbonyl products supports the idea that the electrons in the benzene ring are delocalized and can participate in reactions that lead to these products.

### Conclusion
The ozonolysis of 1,2-dimethylbenzene (o-xylene) produces acetophenone and benzaldehyde, which supports the Kekulé structure of benzene by demonstrating the presence of resonance and the ability of the benzene ring to participate in reactions that lead to the formation of specific products.

---