Among the following, the conformation that corresponds to the most stable conformation of meso-butane-2,3-diol is -
(A)(see structure)
(B)(see structure)✓ Correct
(C)(see structure)
(D)(see structure)
Answer: (B)
Solution
Meso-butane-2,3-diol has two chiral centers with opposite configurations. The most stable conformation is the one that allows intramolecular hydrogen bonding between the two hydroxyl groups. In the Newman projection, this occurs when the two OH groups are gauche to each other, minimizing steric repulsion between the methyl groups while allowing H-bonding. Option (B) shows this arrangement with the OH groups positioned to form an intramolecular hydrogen bond.
JEE Advanced · 2021 · 03 Oct 2021 · Paper 1 · Single correct option