Complete the reaction :
`C_(6)H_(6) overset(O_(3))toA overset(Zn, H_(2)O)toB`

Answer

To complete the reaction given in the question, we will follow the steps of ozonolysis of benzene (C₆H₆) and then the subsequent reaction with zinc and water.

### Step-by-Step Solution:

1. **Identify the Reaction**: The first step involves the ozonolysis of benzene (C₆H₆) using ozone (O₃). Ozonolysis is a reaction where ozone cleaves double bonds in alkenes or alkynes, but in the case of benzene, it leads to the formation of a cyclic ozonide.

2. **Reaction with Ozone**: When benzene reacts with ozone, it forms a compound known as benzene triazonide (A). The structure of benzene has alternating double bonds, and the ozone will insert itself between these carbons, resulting in a cyclic structure.

- **Structure of A**: The ozonolysis of benzene leads to the formation of benzene triazonide, which can be represented as:
\[ \text{C}_6\text{H}_6 + 3 \text{O}_3 \rightarrow \text{C}_6\text{H}_6(\text{O}_3)_{3} \quad (\text{Benzene triazonide}) \]

3. **Reduction with Zinc and Water**: The next step involves the reduction of benzene triazonide (A) using zinc (Zn) and water (H₂O). This reaction typically leads to the formation of carbonyl compounds.

- **Formation of B**: In this case, the ozonide will break down to form glyoxal (B), which is a dialdehyde. The reaction can be summarized as:
\[ \text{C}_6\text{H}_6(\text{O}_3)_{3} + \text{Zn} + \text{H}_2\text{O} \rightarrow 3 \text{C}_2\text{H}_2\text{O}_2 \quad (\text{Glyoxal}) \]

4. **Final Products**: The final products of the reaction sequence are:
- **A**: Benzene triazonide (C₆H₆(O₃)₃)
- **B**: Glyoxal (C₂H₂O₂)

### Summary of the Reaction:
\[ \text{C}_6\text{H}_6 \overset{\text{O}_3}{\rightarrow} \text{C}_6\text{H}_6(\text{O}_3)_{3} \overset{\text{Zn, H}_2\text{O}}{\rightarrow} 3 \text{C}_2\text{H}_2\text{O}_2 \]