Chapter 4, Problem 4.8P

Interpretation Introduction

Interpretation:

The more stable of the two species A and B is to be determined.

Concept introduction:

A chair flip converts one cyclohexane chair conformer to the other. This also changes the orientations of the hydrogen atoms. The ones that were in axial positions initially move to equatorial positions and vice versa. In cyclohexane, these are indistinguishable. However, if one or more of these hydrogens is/are substituted by other atoms, the two can be distinguished. The stability of the conformer depends on orientation of the substituents. This is particularly true of bulky substituents. Large substituents are more stable in equatorial position. In axial position, steric interaction with the hydrogen atoms (or other groups) on the 3^rd carbon reduce the stability of the conformer with bulky substituent in an axial position.