Drawing Cyclohexane Chair Structures

Drawing cyclohexane ring structures and showing ring inversion is a fundamental skill in organic chemistry. Let's break down the steps to help you master this:

Step-by-Step Guide to Drawing Cyclohexane and Showing Ring Inversion

1. Draw Two Diagonal Parallel Lines

• Start by drawing two parallel lines that are slightly offset diagonally.

• The lower line represents the side of the ring that is closer to you (in front), and the upper line represents the side that is further away (in the back).

2. Add the Carbon at One End

• Connect the parallel lines by adding a carbon atom with two bonds—both leading up as shown. This is one of the six carbons in the cyclohexane ring.

3. Add the Carbon at the Other End

• At the other end connect the parallel lines with another carbon atom and two lines (bonds) both leading down as shown. This completes the two ends of the cyclohexane ring.

4. Draw the Axial Bonds on the Top of the Ring

• At each apex (corner) on the top of the ring, draw an axial bond pointing upwards.  Axial bonds alternate up and down from carbon to carbon, but they are always parallel to the ring’s vertical axis.

• There should be three axial bonds pointing up on the top side of the ring.

5. Draw the Axial Bonds on the Bottom of the Ring

• At each apex on the bottom of the ring, draw the other three axial bonds pointing downwards. These bonds should alternate with the ones on the top.

• This completes all six axial bonds (three up and three down).

6. Draw the Equatorial Bonds

• Now, draw the equatorial bonds. Equatorial bonds extend outward from the ring in a way that’s approximately parallel to the ring’s ‘equator.’  At each carbon, the equatorial bond points slightly up or down, opposite to the direction of the axial bond at that same carbon.

• For example, if you start at one carbon, the equatorial bond will be parallel to the bond that is two carbons away in the ring.

• The equatorial bonds are drawn in red to distinguish them from axial bonds below.

Tips for Practice:

• Use Models: If you have a molecular model kit, build a cyclohexane ring to visualize the axial and equatorial positions or play with the following structure.  Hydrogen atoms in axial positions are show in green and equatorial in blue.  If you imagine the chair structure is a wheel then the axial protons would be parallel to the axle and the equatorial protons are around the "equator" of the ring.  

   

• Practice Drawing: Repeatedly draw the chair conformation and practice the ring flip until you can do it quickly and accurately.

• Check Your Work: Compare your drawings with textbook examples or online resources to ensure accuracy.