# Often asked: How To Draw The Most Stable Chair Conformation?

## Cyclohexane Chair Conformation Stability: Which One Is Lower Energy?

How Do You Draw The Most Stable Conformation Of A Cyclohexane Chair? You’ve been given a structure and asked to draw the most stable conformation.

### 1. A-Values Are A Useful Measure Of Bulkiness

The energy difference in kcal/mol between axial and equatorial conformers on a cyclohexane ring was discussed in the previous post. The greater the A-value (bulk), the more favoured the equatorial conformer will be.

### 2. A-Values Are Additive

Calculating the torsional strain of a cyclohexane chair is as simple as adding up the A values of the axial groups in any chair conformation. Because A values are additive, adjacent carbons do not bump into one another.

### 3. Example: Determining The Most Stable Conformation Of cis- AndÂ transâ€“ 1,2-Dimethylcyclohexane

We can use the A-values to determine which molecule is the most stable by drawing the two chair conformations of cis-1,2-dimethylcyclohexane and trans-1,.2-dimer and seeing which one has the highest energy.

### 4. To Determine Chair Conformation Stability, Add Up The A-Values For Each Axial Substituent. The Lower The Number The More Stable It Is

The di-equatorial conformer of trans-1,2,dimethylcyclohexane is the most stable of the two isomers of 1,2-dimethylcylohexane, and now that we’ve drawn all four possible isomers, we can rank them in order of stability.

### 5. Summary: Chair Conformation Stability

We’ll talk about 0cyclohexanoic rings in the next post, and see how we can use what we already know about them to learn more about them.

### Notes

The 1,2-di-t-butyl cyclohexane is an exception to the “A values are additive” assumption, as the diaxial conformation is favored by 6.2 kcal/mol in the trans isomer! See the References section for more information.

We recommend reading:  How To Draw A Pencil Step By Step?

### (Advanced) References and Further Reading

In cyclohexane, A-values are thermodynamic preferences for a substituent to be in the axial or equatorial position; the total energy derived gives the difference in free energy between the all-axial and all-equatorial conformations.

## How do you determine the most stable chair conformation?

Add up the A-Values for each Axial Substituent to determine chair conformation stability; the lower the number, the more stable it is.

## Which chair conformation is most stable?

The chair form of cyclohexane is the most stable conformation; the C-C-C bonds are very close to 109.5sup>o/sup>, so it is almost free of angle strain, and it is also fully staggered, so it is free of torsional strain.

## What is the most stable chair conformation for the following molecule?

Unlike the 2-D diagrams, cyclohexane exists in several 3-D conformations, the most stable of which is the chair conformation, which has the least ring and torsional strain. Other chair conformations include gauche, anti, eclipsed, and staggered.

## What makes a chair conformation stable?

The chair conformation is more stable because there is no steric hindrance or steric repulsion between the hydrogen bonds; however, the equitorial form will be the most stable because the hydrogen atoms, or possibly other substituents, will not be touching each other.

## Which of a )-( D is the most stable conformation?

As a result, the chair conformation (Option D) is the most stable cyclohexane conformation.

## Is chair conformation more stable than boat?

The chair conformation of cyclohexane is more stable than the boat conformation because the C-H bonds are equally axial and equatorial in the chair conformation, i.e., six of the twelve C-H bonds are axial and six are equatorial, and each carbon has one axial and one equatorial C-H bond.

We recommend reading:  How To Draw A Cute Teddy Bear?

## Why is a 1/3 cis disubstituted cyclohexane?

Because the methyl groups are not on adjacent carbons in the cyclohexane rings, gauche interactions are not possible. Cis and trans stereoisomers of 1,3-dimethylcyclohexane The other conformer has both methyl groups in equatorial positions, resulting in no 1,3-diaxial interaction.

## Is a chair flip an enantiomer?

When a chair conformation “flips” from equatorial to axial and vice versa, there is no inversion of configuration; they are technically conformational isomers or the same molecule.

## Are chair flips conformational isomers?

The Point of This Post Is To Describe How These Two Conformations Can Be Converted Into Each Other Through A Cyclohexane “Chair Flip” Same connectivity, different shape u2013 if ever there was a definition of ” conformational isomers,” this is it. The point of this post is to describe how these two conformations can be converted into each other through a series of bond rotations we call a “chair flip.”