Ozonolysis of an alkene produces only one dicarbonyl compound. The structure of the alkene is

Options

A. `CH_3 -CH =CH-CH_3`
B.
C.
D. `CH_3-CH=CH-CH=CH_3`

Explanation

To determine the structure of the alkene that, upon ozonolysis, produces only one dicarbonyl compound, we can follow these steps:

### Step 1: Understand Ozonolysis
Ozonolysis is a reaction where ozone (O₃) reacts with alkenes to form carbonyl compounds. The reaction involves the formation of an ozonide intermediate, which upon hydrolysis yields aldehydes or ketones.

### Step 2: Identify the Alkene
We need to find an alkene that, when ozonolyzed, yields only one type of dicarbonyl compound. A dicarbonyl compound contains two carbonyl (C=O) groups.

### Step 3: Analyze Possible Alkenes
Let’s consider the alkenes:

1. **Alkene A**: If we take 1-butene (CH₂=CH-CH₂-CH₃), ozonolysis would yield two different carbonyl compounds (acetaldehyde and propan-2-one).

2. **Alkene B**: If we take 2-butene (CH₃-CH=CH-CH₃), ozonolysis would yield two identical carbonyl compounds (two molecules of butanal).

3. **Alkene C**: If we take 1,3-butadiene (CH₂=CH-CH=CH₂), ozonolysis would yield two different carbonyl compounds (two molecules of acetaldehyde).

4. **Alkene D**: If we take 2-pentene (CH₃-CH=CH-CH₂-CH₃), ozonolysis would yield two different carbonyl compounds (two molecules of pentanal).

### Step 4: Determine the Correct Alkene
The only alkene that yields a single dicarbonyl compound is **Alkene B (2-butene)**, which produces two molecules of butanal (CH₃-CH₂-CHO).

### Step 5: Conclusion
Thus, the structure of the alkene that produces only one dicarbonyl compound upon ozonolysis is **2-butene**.

### Final Answer
The structure of the alkene is **2-butene (CH₃-CH=CH-CH₃)**.

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