Q4-34E - Organic Chemistry (Mcmurry)

Question

Hydrocortisone, a naturally occurring hormone produced in the adrenal glands, is often used to treat inflammation, severe allergies, and numerous other conditions. Is the indicated $\mathbf{-}\mathbf{OH}$ group axial or equatorial?

Step-by-Step Solution

Answer

The   $\text{-OH}$group of hydrocortisone indicates the axial position.

Step 1: Chair form of cyclohexane

Four conformations are possible for cyclohexane: a chair, twist boat, boat, and half chair. Among all the four conformations chair form of cyclohexane is considered a very stable one. Chair conformation of cyclohexane is as follows;

Here ‘a’ indicates the axial position and ‘e’ indicates the equatorial position.

Step 2: The - OH group of hydrocortisone

The $\text{-OH}$ group of hydrocortisone indicates axial position if we compare it with the above chair model of cyclohexane.