Propanal and pentan-3-one are the ozonolysis products of an alkene? What is the structural formula of the alkene?

Explanation

To determine the structural formula of the alkene that yields propanal and pentan-3-one as ozonolysis products, we can follow these steps:

### Step 1: Understand Ozonolysis
Ozonolysis is a reaction where ozone (O₃) is added to an alkene or alkyne, resulting in the cleavage of the double bond and the formation of carbonyl compounds (aldehydes or ketones).

### Step 2: Identify the Products
The products given are:
- Propanal (an aldehyde)
- Pentan-3-one (a ketone)

### Step 3: Analyze the Structure of the Products
1. **Propanal** has the structure:
\[ \text{CH}_3\text{CH}_2\text{CHO} \]
This indicates that one end of the alkene must lead to the formation of this aldehyde.

2. **Pentan-3-one** has the structure:
\[ \text{CH}_3\text{C(=O)}\text{CH}_2\text{CH}_2\text{CH}_3 \]
This indicates that the other end of the alkene must lead to the formation of this ketone.

### Step 4: Construct the Alkene
To find the alkene that would yield these products upon ozonolysis, we need to consider how the double bond in the alkene can be positioned to produce both products.

Assuming the alkene has the structure:
\[ \text{CH}_3\text{CH}_2\text{C}=\text{C}\text{CH}_2\text{CH}_3 \]
This alkene is 4-ethylhex-3-ene, where:
- The double bond is between the third and fourth carbon atoms.
- The ozonolysis of this alkene would yield propanal and pentan-3-one.

### Step 5: Confirm the Products
When ozonolysis occurs:
1. The double bond between C3 and C4 will break.
2. The carbon at C3 will form a carbonyl group leading to propanal.
3. The carbon at C4 will form a carbonyl group leading to pentan-3-one.

### Final Structural Formula
The structural formula of the alkene is:
\[ \text{CH}_3\text{CH}_2\text{C}=\text{C}\text{CH}_2\text{CH}_3 \]
or as 4-ethylhex-3-ene.

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