Question

Aldosterone is in equilibrium with its cyclic hemiacetal. Draw the hemiacetal form of aldosterone.

Short answer

Hemiacetal form of aldosterone:

Step-by-step solution

Hemiacetal form

When aldehyde reacts with alcohol in a molecule, it is called its Hemi acetal form. It occurs when carbonyl of aldehyde is near with the hydroxyl group of alcohol and formation of hemiacetal other when proton of hydroxyl group occurs with the loss of water.

Hemiacetal form of aldosterone

Structure of aldosterone:

As clearly visible that the carbonyl of aldehyde is present near the hydroxyl group hemiacetal formation occurs by the protonation of hydroxyl leads to the form of oxonium ion and attack on the carbonyl carbon shifting the electron density toward negative charge oxygen, which gained proton and forms hydroxyl hence intramolecular hemiacetal formed as shown:

Hemiacetal form of aldosterone