To determine the number of geometrical isomers possible for the diene that produces 2 moles of ethanal and 1 mole of propan-1,3-diol upon reductive ozonolysis, we can follow these steps:
### Step 1: Identify the products
The products of the reductive ozonolysis are:
- 2 moles of ethanal (acetaldehyde, CH₃CHO)
- 1 mole of propan-1,3-diol (CH₂(OH)CH(OH)CH₃)
### Step 2: Construct the corresponding alkene
From the products, we can deduce the structure of the corresponding alkene. The presence of ethanal indicates that there are two carbonyl groups (C=O) and the propan-1,3-diol indicates that there are two hydroxyl groups (-OH) on the first and third carbon atoms of a three-carbon chain.
To find the corresponding diene, we can visualize the structure:
- Ethanal contributes two carbon atoms.
- Propan-1,3-diol contributes three carbon atoms.
Thus, the diene has a total of 5 carbon atoms.
### Step 3: Draw the diene structure
The diene can be represented as follows:
- C=C-C=C (where the double bonds are between the first and second, and the third and fourth carbon atoms).
### Step 4: Determine the possible geometrical isomers
To find the geometrical isomers, we need to check for the presence of double bonds in the diene structure that can exhibit cis/trans (E/Z) isomerism.
1. **Identify double bonds**: In our diene structure, we have two double bonds.
2. **Check for substituents**: Each double bond must have different substituents to allow for geometrical isomerism.
### Step 5: Count the geometrical isomers
For each double bond:
- If we have different groups attached to the double bond, we can have both cis and trans forms.
Assuming the diene has the following structure:
- H₂C=CH-CH=CH₂ (with substituents on the ends)
1. For the first double bond (C1=C2), we can have:
- Cis (both substituents on the same side)
- Trans (substituents on opposite sides)
2. For the second double bond (C3=C4), we can also have:
- Cis
- Trans
### Step 6: Total geometrical isomers
- For each double bond, we have 2 forms (cis and trans).
- Therefore, if both double bonds can exhibit geometrical isomerism independently, we can calculate the total as follows:
- 2 (from first double bond) x 2 (from second double bond) = 4 geometrical isomers.
### Conclusion
Thus, the total number of geometrical isomers possible for the diene is **4**.
