5-oxohexanal is obtained by ozonolysis of:

Options

A.
B.
C.
D.

Answer

To determine which compound yields 5-oxohexenol upon ozonolysis, we need to analyze the given options step by step. Ozonolysis is a reaction where alkenes react with ozone (O₃) to form ozonides, which can then be reduced to carbonyl compounds (aldehydes or ketones) through hydrolysis.

### Step-by-Step Solution:

1. **Understanding Ozonolysis**:
- Ozonolysis involves the cleavage of carbon-carbon double bonds in alkenes, resulting in the formation of carbonyl compounds. The general reaction can be represented as:
\[ RCH=CHR' \xrightarrow{O_3} RCHO + R'CHO \]
- The carbon-carbon double bond breaks, and carbonyl (C=O) bonds are formed.

2. **Identifying the Target Compound**:
- We need to obtain 5-oxohexenol, which has the structure:
\[ CH₃-CH₂-CH₂-CHO-CH=CH₂ \]
- This indicates that after ozonolysis, we should have a total of 6 carbons with a carbonyl group at the 5th position.

3. **Analyzing Each Option**:
- **Option A**: A 5-membered ring with a double bond.
- Upon ozonolysis, this would yield a product with 7 carbons (5 from the ring and 2 from the chain), leading to a compound that is not 5-oxohexenol.
- **Option B**: A compound with a double bond and a methyl group.
- Ozonolysis would yield a product that results in a structure not matching 5-oxohexenol.
- **Option C**: A compound that results in two aldehyde groups upon ozonolysis.
- This would also not yield 5-oxohexenol.
- **Option D**: A straight-chain alkene with a double bond.
- Ozonolysis here would break the double bond and yield:
- One side: CH₂=O (aldehyde)
- Other side: C=O (ketone)
- The resulting structure matches 5-oxohexenol.

4. **Conclusion**:
- After analyzing all options, **Option D** is the correct choice as it leads to the formation of 5-oxohexenol upon ozonolysis.

### Final Answer:
**5-oxohexenol is obtained by ozonolysis of the compound in Option D.**