Cyclohexane - Equatorial Preference

This is the #1 thing you need to know about cyclohexane. So let’s get right into it.

Determining the Best Position

  • Blue = Axial. This position sucks, it’s really cramped up. Large groups can’t stand it.
  • Green = Equatorial. This position is awesome. Large groups want to flip to this position

Determining Equatorial Preference

We always want to draw our chairs with the largest groups equatorial. If they are axial, we need to flip the chair. 

Example: Draw the following chair in the most stable conformation.

4m

Don’t worry about drawing this problem out correctly on the first try, as long as you know how to flip it to the correct chair, that’s all that matters. 

Example: Draw the MOST STABLE conformation of cis-1-tert-butyl-4-methylcyclyhexane.

 

3m

Hint: If you don’t know what neopentyl is, it’s ok. Obviously it has 5 carbons, so keep that in mind when deciding equatorial preference!

Example: Draw the LEAST STABLE conformation of trans-1-tert-butyl-3-neopentylcyclohexane.

5m