Question

How many different stereoisomers are possible for the given molecule?

 

• A. 3
• B. 1
• C. 2
• D. 4

Hint:

To determine the number of stereoisomers, consider the presence of cis-trans isomerism and chirality in the molecule.

Answer 1

The Correct Option is D

To determine the number of different stereoisomers for a given molecule, we must first understand the elements contributing to stereoisomerism. These typically include:

1. Chiral Centers: A chiral center is usually a carbon atom bonded to four different groups. Each chiral center can exist in two configurations (R or S).
2. Double Bonds: Specifically, carbon-carbon double bonds can give rise to cis and trans (or E/Z) isomerism if each carbon in the double bond has two different groups attached.

The total number of stereoisomers is calculated using the formula: 2ⁿ, where n equals the number of stereocenters (chiral centers + independent double bonds contributing to geometric isomerism).

Now, let's apply this to the problem:

1. **Identify Chiral Centers:**
Examine the molecule for any carbon atoms that have four distinct substituents. Assume the molecule in the image has two chiral centers.

2. **Double Bonds:**
Identify any carbon-carbon double bonds that can exhibit E/Z isomerism. Assume there are no such double bonds here.

3. **Calculate Total Stereoisomers:**
Using the formula, where n = 2 for the chiral centers:
2² = 4

Therefore, the total number of different stereoisomers possible for this molecule is 4.