Linear polyenes on ozonolysis gives two moles of acetaldehyde and one mole of propanedinal. Linear polyene will be

Options

A. Alkadiene
B. Alkatriene
C. Alkatetraene
D. Alkapentaene

Answer

To solve the problem, we need to determine the structure of the linear polyene that, upon ozonolysis, yields two moles of acetaldehyde and one mole of propanediol. Here’s a step-by-step breakdown of how to approach this:

### Step 1: Identify the Products
The products of ozonolysis are:
- 2 moles of acetaldehyde (CH3CHO)
- 1 mole of propanediol (CHO-CH2-CHO)

### Step 2: Understand Ozonolysis
Ozonolysis involves the cleavage of double bonds in alkenes to form carbonyl compounds (aldehydes or ketones). In this case, we are performing reductive ozonolysis, which means we will only produce aldehydes and ketones.

### Step 3: Analyze the Products
From the products:
- Acetaldehyde (CH3CHO) contains a 2-carbon chain with a carbonyl group at one end.
- Propanediol (CHO-CH2-CHO) is a 3-carbon compound with two aldehyde groups.

### Step 4: Determine the Structure of the Polyene
To produce these products, we need to consider a linear polyene that can yield:
- 2 acetaldehydes (from two double bonds)
- 1 propanediol (from one double bond)

### Step 5: Construct the Polyene
A possible structure for the linear polyene is:
- 1,3-butadiene (H2C=CH-CH=CH2)

When ozonolysis occurs on this compound, the double bonds will break, leading to the formation of the products mentioned.

### Step 6: Confirm the Structure
1. **Ozonolysis of 1,3-butadiene:**
- The double bond between the first and second carbon will yield one acetaldehyde.
- The double bond between the third and fourth carbon will yield another acetaldehyde.
- The remaining structure after ozonolysis will yield propanediol.

### Conclusion
The linear polyene that gives two moles of acetaldehyde and one mole of propanediol upon ozonolysis is **1,3-butadiene**.