Question

A student wanted to dry some diacetone alcohol and allowed it to stand over anhydrous potassium carbonate for a week. At the end of the week, the sample was found to contain nearly pure acetone. Propose a mechanism for the reaction that took place.

Short answer

The reverse aldol condensation reaction is when thereaction is taken towards the backward direction. It is also known as aretro aldol condensation reaction.

This reactionidentifies the unknown carbonyl compound used to carry out the aldol condensation reaction.

Step-by-step solution

Step 1: Reverse Aldol condensation Reaction

The reverse aldol condensation reaction is when thereaction is taken towards the backward direction. It is also known as aretro aldol condensation reaction.

This reactionidentifies the unknown carbonyl compound used to carry out the aldol condensation reaction.

Reverse Aldol condensation reaction of diacetone alcohol                                              

When potassium carbonate is added to 4-hydroxy-4-methyl pentane-2-one (Diacetonealcohol) reverse aldol condensation reaction takes place as all the steps in aldol condensation are reversible and at the equilibrium formation of acetone is favored.

Reverse aldol condensation of 4-hydroxy-4-methyl pentane-2-one