An unsaturated hydrocarbon was treated with ozone and resulting ozonide on hydrolysis gives 2-pentanone and acetaldehyde. What is the structure of alkene?

Options

A. `C_(3)H_(7)-CH=CH-CH_(3)`
B.
C.
D.

Explanation

To determine the structure of the unsaturated hydrocarbon (alkene) that, upon ozonolysis, yields 2-pentanone and acetaldehyde, we can follow these steps:

### Step 1: Understand the Products
The products of ozonolysis are given as 2-pentanone and acetaldehyde.
- 2-pentanone has the structure:
\[ CH_3-CO-CH_2-CH_2-CH_3 \]
- Acetaldehyde has the structure:
\[ CH_3-CHO \]

### Step 2: Analyze the Ozonolysis Reaction
In ozonolysis, the alkene reacts with ozone to form an ozonide, which upon hydrolysis breaks down into carbonyl compounds (aldehydes or ketones). The reaction can be summarized as:
\[ \text{Alkene} + O_3 \rightarrow \text{Ozonide} \rightarrow \text{Aldehydes/Ketones} \]

### Step 3: Determine the Alkene Structure
To find the alkene that produces these specific carbonyl compounds, we can deduce the structure based on the products:
- The carbon skeleton of 2-pentanone suggests that one of the carbonyl groups comes from a ketone formed by breaking the double bond in the alkene.
- The presence of acetaldehyde suggests that the other carbonyl group comes from an aldehyde.

### Step 4: Construct Possible Alkene Structures
Given that we need an alkene that can yield both products:
- The carbon chain must be long enough to accommodate both products.
- The double bond must be positioned such that upon ozonolysis, it can yield both 2-pentanone and acetaldehyde.

Let’s consider the alkene 3-hexene:
\[ CH_3-CH_2-CH=CH-CH_2-CH_3 \]

### Step 5: Perform Ozonolysis on 3-Hexene
When 3-hexene undergoes ozonolysis, the double bond breaks and forms:
- One part leads to 2-pentanone:
\[ CH_3-CO-CH_2-CH_2-CH_3 \]
- The other part leads to acetaldehyde:
\[ CH_3-CHO \]

### Conclusion
Thus, the structure of the unsaturated hydrocarbon (alkene) is **3-hexene**.