Question

g Draw the most stable chair conformation for each of the following compounds (a) Cis-1-ethyl-2-methyl cyclohexane (b) Trans-1-ethyl-2-methyl cyclohexane (c) Which one is more stable, a or b

Answer 1

See explanation

Step-by-step explanation:

Image 1 is the chair conformation of trans-1-ethyl-2-methyl cyclohexane while image 2 is the chair conformation of Cis-1-ethyl-2-methyl cyclohexane.

Now let us look at the two structures closely. In the chair conformation, the more stable structure is the structure that has the bulky groups placed in the equatorial position.

Clearly, in trans-1-ethyl-2-methylcyclohexane, the ethyl and methyl groups are found to be in equatorial positions. Hence, trans-1-ethyl-2-methylcyclohexane is more stable in the chair conformation than cis-1-ethyl-2-methyl cyclohexane which has its methyl and ethyl groups in axial position.