The olefin which on ozonolysis gives `CH_(3)CH_(2)CHO` and `CH_(3)CHO` is

Options

A. But -1 - ene
B. But -2- ene
C. Pent -1- ene
D. Pent -2-ene

Answer

To solve the problem of identifying the olefin that, upon ozonolysis, yields `CH₃CH₂CHO` (butanal) and `CH₃CHO` (acetaldehyde), we can follow these steps:

### Step 1: Understand Ozonolysis
Ozonolysis is a reaction where an alkene reacts with ozone (O₃) to form ozonides, which can then be hydrolyzed to yield carbonyl compounds (aldehydes or ketones).

### Step 2: Identify the Products
The products we need to obtain from the ozonolysis are:
- Butanal (`CH₃CH₂CHO`)
- Acetaldehyde (`CH₃CHO`)

### Step 3: Determine the Structure of the Olefin
To find the correct olefin, we need to consider the structure that can lead to these products after ozonolysis.

1. **Butanal** has a 4-carbon chain with an aldehyde functional group at one end.
2. **Acetaldehyde** has a 2-carbon chain with an aldehyde functional group.

### Step 4: Consider Possible Olefins
We need to consider olefins (alkenes) that can lead to the formation of these products. The likely candidates are:
- But-1-ene
- But-2-ene
- Pent-1-ene
- Pent-2-ene

### Step 5: Analyze Each Olefin
1. **But-1-ene**:
- Structure: `CH₂=CH-CH₂-CH₃`
- Ozonolysis would yield products that do not match our desired aldehydes.

2. **But-2-ene**:
- Structure: `CH₃-CH=CH-CH₃`
- Ozonolysis of but-2-ene leads to the formation of butanal and acetaldehyde.

3. **Pent-1-ene**:
- Structure: `CH₂=CH-CH₂-CH₂-CH₃`
- Ozonolysis does not yield the desired products.

4. **Pent-2-ene**:
- Structure: `CH₃-CH=CH-CH₂-CH₃`
- Ozonolysis does not yield the desired products.

### Step 6: Conclusion
After analyzing the possible olefins, we find that **but-2-ene** is the olefin that, upon ozonolysis, produces the desired products: butanal (`CH₃CH₂CHO`) and acetaldehyde (`CH₃CHO`).

### Final Answer
The olefin which on ozonolysis gives `CH₃CH₂CHO` and `CH₃CHO` is **but-2-ene**.