In chair conformation, where does the larger substituent prefer to be positioned?

In chair conformations of cyclohexane, steric interactions play a significant role in determining the preferred positioning of substituents attached to the cyclohexane ring. Larger substituents experience greater steric hindrance, which can lead to increased energy and strain when they are positioned in certain ways.

When a substituent is in the axial position, it is perpendicular to the plane of the ring, causing it to interact unfavorably with other axial hydrogen atoms located on the same side of the ring. This leads to higher steric repulsion and destabilizes the conformer. In contrast, an equatorial position allows the substituent to extend outward from the ring, minimizing these steric interactions with other substituents or hydrogen atoms on the ring.

Consequently, larger substituents tend to occupy the equatorial position in a chair conformation. This positioning reduces steric strain and allows for a more stable arrangement. Therefore, the preference for larger substituents to be equatorial is rooted in their need to minimize steric hindrance and maximize stability within the molecular structure.