Chemistry - GOC Question with Solution | TestHub
Explain the following reaction in mechanistic terms. Show arrow pushing. The product formed is :
Options:
Answer:
Solution:
This is an example of a Claisen rearrangement, an electrocyclic reaction that does not involve charges. Similar to the Diels-Alder reaction, electron pairs move, and their movement can be illustrated using arrow pushing.
The mechanism, illustrated below, involves a lone pair of electrons from the oxygen moving into the aromatic ring. The aromatic ring then adds electrons to the double bond, which subsequently migrates, and the carbon-oxygen bond is cleaved. While the expected product might be the ketone, spontaneous conversion to the enol form is facilitated by the stability of the resulting aromatic ring. Thus, the illustrated product is formed. All these steps occur concurrently; like the Diels-Alder reaction (and all electrocyclic reactions), there is no net loss or gain of bonds.
Answer: (D).
