Q15-55E - Organic Chemistry (Mcmurry)

Question

The compound below is the product initially formed in a Claisen rearrangement (Section 18-4). This product is not isolated but tautomerizes to its enol form. Give the structure of the enol and provide an explanation as to why the enol tautomer is favored.

Step-by-Step Solution

Answer

Step 1: Claisen rearrangement

The Claisen rearrangement is a chemical reaction that offers the formation of a carbon-carbon bond. It is a powerful carbon-carbon bond-forming reaction.

Step 2: Tautomerisation

The tautomerization of the product of the Claisen rearrangement is as shown:

The enol generated in this tautomerization reaction is phenol which is an aromatic compound. As the aromatic compounds are more stable than the non-aromatic compounds due to the delocalization of the p electron cloud, the equilibrium shifts towards the right side.