NEET levelSingle correct optionDifficulty 1 of 3ap185
On heating with dilute acid, pinacol (2,3-dimethylbutane-2,3-diol) undergoes the pinacol-pinacolone rearrangement to give
A2,2-dimethylbutanal
B3,3-dimethylbutan-2-ol
C3,3-dimethylbutan-2-one (pinacolone)
D2,3-dimethylbut-2-ene
Answer: C
Protonation and loss of water give a tertiary carbocation, then a methyl group migrates to the cationic carbon. Loss of HX+ from the protonated carbonyl gives (CHX3)X3C−CO−CHX3, 3,3-dimethylbutan-2-one (pinacolone).