The least stable conformation of 3-bromo-2-methylpentane,viewed through the C-2-C-3 bond (i.e.,C-2 in the front,C-3 in the back):

Question

Quizplus · Accepted Answer

In conformation III, the bromine and methyl groups are in eclipsed positions, leading to steric strain and making it the least stable conformation. In contrast, in conformations I, II, IV, and V, the groups are staggered, reducing steric interactions and making them more stable than III.

The Least Stable Conformation of 3-Bromo-2-Methylpentane,viewed Through the C-2-C-3 Bond