Dienone–Phenol Rearrangement
In presence of acid, 4,4-disubstituted cyclohexadienone is converted into a stable 3,4-disubstituted phenol. This is known as dienone–phenol rearrangement.
Similar rearrangement is possible with a 2,2-disubstituted cyclohexadienone to 2,3-disubstituted phenol and/or a 2,6-disubstituted phenol.
The migratery aptitude for the two different groups present at 4,4 position can be determined by comparing the relative stability of the intermediate carbocation formed during rearrangement.
Similar rearrangement is possible with a 2,2-disubstituted cyclohexadienone to 2,3-disubstituted phenol and/or a 2,6-disubstituted phenol.
Mechanism of Dienone–Phenol Rearrangement
The possible mechanism is given below-The migratery aptitude for the two different groups present at 4,4 position can be determined by comparing the relative stability of the intermediate carbocation formed during rearrangement.