Question

Which of the following is the most stable conformer of butane-2,3-diol?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

Conformer (b) is more stable than (a).
Here, (a) is staggered (anti) conformer and (b) is staggered gauche conformer of butane-2,3 diol.
Generally, staggered conformers are most stable than the eclipsed and gauche conformer due to less torsional strain but here gauche conformer of butane-2,3 diol is stable than the staggered conformer due to the formation of hydrogen bonding.

(c) and (d) are not conformers of butane-2, 3-diol.
Hence, (b) is stable conformers of butane-2, 3-diol.