Consider the following reaction `(A)overset((i)O_3)underset((ii)H_2"O"//Zn)rarrCH_3-overset(O)overset(||)C-CH_2-overset(O)overset(||)C-CH_2-overset(O)overset(||)C-CH_3+3HCHO` Compound 'A' will be

Options

A. `CH_3-overset(O)overset(||)C-CH_2-overset(O)overset(||)C-CH_2-overset(CH_2)overset(||)C-CH_3`
B. `CH_3-overset(O)overset(||)C-CH_2-overset(CH_2)overset(||)C-CH_2-overset(O)overset(||)C-CH_3`
C. `CH_3-overset(CH_2)overset(||)C-CH_2-overset(CH_2)overset(||)C-CH_2-underset(CH_3)underset(|)C=CH_2`
D. All of these

Answer

To determine the compound 'A' in the given reaction, we need to analyze the process of reductive ozonolysis and how it affects alkenes. Here’s a step-by-step breakdown of the solution:

### Step-by-Step Solution:

1. **Understanding Reductive Ozonolysis**:
- Reductive ozonolysis involves the reaction of an alkene with ozone (O₃) followed by reduction (usually with zinc and water). This reaction cleaves the double bond of the alkene and forms carbonyl compounds (aldehydes and/or ketones).

2. **Analyzing the Products**:
- The reaction produces a ketone and 3 moles of formaldehyde (HCHO). The presence of 3 moles of formaldehyde indicates that the original compound must have 3 terminal methylene groups (–CH₂–) adjacent to the double bonds.

3. **Identifying the Structure of Compound 'A'**:
- Since we have 3 moles of formaldehyde formed, it suggests that the original compound 'A' must be a symmetrical alkene with three double bonds that can yield formaldehyde upon ozonolysis.
- The structure of compound 'A' can be inferred to be an alkene with the following structure:
\[ CH_3-CH=CH-CH_2-CH=CH-CH_2-CH=CH-CH_3 \]
- This structure has three double bonds, and when ozonolysis occurs, it will yield three formaldehyde molecules and one ketone.

4. **Performing the Ozonolysis**:
- When ozonolysis occurs on this compound, the double bonds will break, leading to the formation of three formaldehyde molecules and a ketone. The ketone will have the structure:
\[ CH_3-C(=O)-CH_2-C(=O)-CH_2-C(=O)-CH_3 \]
- This confirms that the original compound 'A' is indeed the alkene with three double bonds.

5. **Conclusion**:
- Therefore, compound 'A' is the symmetrical alkene that upon ozonolysis produces the specified ketone and three moles of formaldehyde.

### Final Answer:
Compound 'A' is:
\[ CH_3-CH=CH-CH_2-CH=CH-CH_2-CH=CH-CH_3 \]