1.7 Cycloalkanes and Ring Strain

Cycloalkanes are alkanes that are cyclic –in other words, ringed alkanes or alkanes with rings in them. Cyclohexane is the most stable cycloalkane.

How to draw chair conformations of cyclohexane (follow along!):

Axial vs. Equatorial:

Note: Equatorial positions are more stable (lower energy) than axial for larger groups because of 1,3-diaxial interactions. Placing the largest substituents in the equatorial positions will usually achieve the greatest stability in cyclohexane rings.

Trans vs. Cis cyclohexanes

Cis – two substituents going in same direction
Trans – two substituents going in opposite direction