The major product formed in the following reaction is

Concept:-

Pinacol-Pinacolon Rearrangement:

• The pinacol pinacolone rearrangement is an approach to convert a 1,2-diol to a carbonyl compound under acidic conditions.
• The name of the reaction derives from the rearrangement of pinacol to pinacolone.
• In pinacol pinacolone rearrangement migration of electron-rich substituents occur from a carbon to a cationic carbon atom.
• The general scheme of the Pinacol-Pinacolon rearrangement reaction is given below:

• Lewis acid can enhance the rate of pinacol pinacolone rearrangement reaction.

Explanation:-

• The reaction pathway is shown below:

• From the above reaction, it is shown that in the first step of the reaction, one of the -OH group of the 1,2 diol undergoes adduct formation with Lewis acid BF₃ followed by the formation of a carbocation.
• In the next step, the if undergoes a [1,2] shift/migration of the H atom to give the final product.
• During protonation, the -OH (hydroxyl group) on the secondary carbocation does not undergo adduct formation with Lewis acid BF3, as it will form a less stable carbocation.

Conclusion:-

Hence, the major product formed in the following reaction is