Chapter 4, Problem 59P

Interpretation Introduction

Interpretation:The correct positioned substituent in the cyclohexane derivative should be chosen.

Concept introduction:In chair form, all the $\text{C—C—C}$ bond angle are $109.5°$ . Since this is ideal tetrahedral angle so there is no angular strain in chair form. The staggered $\text{C—H}$ bond further allows for no amount of torsional strain. There are two kinds of hydrogens in cyclohexane namely axial and equatorial indicated as follows:

  

Usually the stable conformations have bulkier groups such as isopropyl, $\mathrm{tert}-butyl$ placed equatorially while small atoms such as hydroxyl hydrogen present axial. This is table as the bulkier group tends to have repulsive interaction with axial hydrogen via $1,3\text{-diaxial}$ interactions.