Point out A in the given reaction sequence
`Aoverset(O_(3)//H_(2)O_(2))rarrBoverset(Delta)rarr2CH_(3)COOH+CO_(2)`

Options

A.
B.
C.
D.

Answer

To determine the compound A in the given reaction sequence, we need to analyze the entire reaction process step by step.

### Step 1: Understanding the Reaction Sequence
The reaction sequence is given as:
\[ A \xrightarrow{O_3/H_2O_2} B \xrightarrow{\Delta} 2 \text{CH}_3\text{COOH} + \text{CO}_2 \]

Here, A is a reactant that undergoes ozonolysis followed by a heating step that produces acetic acid (CH₃COOH) and carbon dioxide (CO₂).

### Step 2: Identifying the Type of Reaction
The first part of the reaction involves ozonolysis, which is a reaction of alkenes with ozone (O₃) followed by a reductive workup (in this case, hydrogen peroxide, H₂O₂). Ozonolysis typically cleaves carbon-carbon double bonds (C=C) to form carbonyl compounds.

### Step 3: Analyzing the Product B
The product B must be a compound that, upon heating, can decarboxylate to yield two moles of acetic acid (CH₃COOH) and one molecule of carbon dioxide (CO₂). This indicates that B must contain two carboxylic acid groups that can lose CO₂ upon heating.

### Step 4: Considering Possible Structures for A
Since we are looking for a compound A that can yield the products mentioned, we need to consider alkenes that, when ozonolyzed, can produce a compound with two carboxylic acid groups.

1. **Cyclopentene**: Ozonolysis would yield butanoic acid, which does not match our product.
2. **Cyclohexene**: This could yield a structure that might not lead to the required products.
3. **Cyclohexa-1,4-diene**: This compound has two double bonds and can produce two moles of acetic acid upon ozonolysis and subsequent heating.
4. **Cyclobuta-1,3-diene**: This would yield oxalic acid, which does not match our product requirement.

### Step 5: Confirming the Correct Option
After analyzing the options:
- **Cyclohexa-1,4-diene** is the only compound that, upon ozonolysis, can yield a structure that can decarboxylate to form two moles of acetic acid and one molecule of carbon dioxide.

### Conclusion
Thus, the compound A is **Cyclohexa-1,4-diene**.