An unsaturated hydrocarbon on ozonolysis gives one mole each of methanal, ethanal and 2-ketopropanal. The structure of the hydrocarbon is

Options

A. `CH_2=CH-CH=CHCH_3`
B. `CH_3CH = CH-CH =CHCH_3`
C. `CH_2=C(CH_3)-CH=CHCH_3`
D. `CH_2=CH-C(CH_3)=CHCH_3`

Explanation

To solve the problem of identifying the structure of the unsaturated hydrocarbon that gives methanal, ethanal, and 2-ketopropanal upon ozonolysis, we can follow these steps:

### Step 1: Understand the Products of Ozonolysis
Ozonolysis of unsaturated hydrocarbons typically cleaves double bonds to form carbonyl compounds. The products given are:
- Methanal (HCHO)
- Ethanal (CH3CHO)
- 2-Ketopropanal (C3H6O2)

### Step 2: Analyze the Products
The products indicate that we have:
1. One carbonyl compound with one carbon (methanal).
2. One carbonyl compound with two carbons (ethanal).
3. One carbonyl compound with three carbons (2-ketopropanal).

### Step 3: Determine the Possible Structure
To find the structure of the original unsaturated hydrocarbon, we need to consider how these products can be formed. The ozonolysis reaction will break the double bond and add oxygen to the resulting fragments.

### Step 4: Construct the Hydrocarbon
Let’s assume the hydrocarbon has a double bond between two carbon atoms. We can start with a structure that has a double bond and enough carbons to yield the required products.

1. **Start with a 5-carbon chain**:
- The hydrocarbon could be pentene (C5H10) since it can yield three products upon ozonolysis.
- The structure could be 2-pentene (CH3-CH=CH-CH2-CH3).

### Step 5: Perform Ozonolysis
When 2-pentene undergoes ozonolysis:
- The double bond between the second and third carbon atoms will be cleaved.
- This will yield:
- Methanal from the terminal carbon (CH2=O).
- Ethanal from the second carbon (CH3CHO).
- 2-Ketopropanal from the third carbon (C3H6O2).

### Step 6: Confirm the Structure
Now we can confirm that the structure of the unsaturated hydrocarbon is indeed 2-pentene (C5H10).

### Final Answer
The structure of the unsaturated hydrocarbon is **2-pentene (CH3-CH=CH-CH2-CH3)**.

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