The following reaction is called the pinacol rearrangement. The reaction begins with an acid-promoted ionization to give a carbocation. This carbocation undergoes a methyl shift to give a more stable, resonance-stabilized cation. Loss of a proton gives the observed product. Propose a mechanism for the pinacol rearrangement.

Transcribed Image Text:

HC CH CHC-CCH HO OH pinacol O CH H2So4. heat CH,-C-C-CH CH3 pinacolone