Question

The more stable species in each pair of conformers are 

• A. II, IV and V
• B. I, IV and V
• C. II, III and V
• D. I, IV and VI

Hint:

Conformers are analyzed based on steric strain. The most stable conformers generally have minimal steric hindrance and favorable electron interactions.

Answer 1

The Correct Option is B

Step 1: Understanding the conformers.
Conformers are different spatial arrangements of a molecule that arise from rotation around single bonds. Stability of conformers is largely influenced by steric strain (such as steric hindrance) and electronic effects. For each pair of conformers, we need to analyze the steric strain and identify the most stable ones.

Step 2: Analyzing the options.
- For the pair I and II, I is the most stable due to less steric hindrance.
- For the pair III and IV, IV is more stable because it avoids unfavorable steric interactions present in III.
- For the pair V and VI, V is more stable due to the optimal positioning of substituents and fewer steric clashes.

Step 3: Conclusion.
The more stable conformers in each pair are I, IV, and V, so the correct answer is (B).