In a substituted cyclohexane, how does the axial position of a bulky substituent influence angle strain and overall stability compared to when it is in the equatorial position?

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Bulky groups in a cyclohexane ring prefer the equatorial orientation because the axial position forces the bond to tilt toward the ring, creating a 60‑degree torsion that pulls the substituent into a crowded space and increases angle strain. In the axial position, the substituent’s bonds are forced into a gauche-like arrangement with neighboring hydrogens, raising steric hindrance and raising the ring’s overall energy. When the same group is placed equatorially, it lies farther from the ring’s interior, minimizing steric clashes and keeping bond angles closer to the ideal 109. 5°, so the ring experiences less angle strain and is more stable. For example, a tert‑butyl group in 1‑tert‑butylcyclohexane prefers the equatorial position, making the compound about 2–3 kcal/mol more stable than its axial isomer.

In a substituted cyclohexane, how does the axial position of a bulky substituent influence angle strain and overall stability compared to when it is in the equatorial position?

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