The video explains the Fries rearrangement, a reaction named after Karl Fries, involving the rearrangement of aryl esters to form ortho and para products. It discusses the role of Lewis and Bronsted-Lowry acids, the reaction's reversibility, and the mechanism involving acylium ions. Crossover studies show intermolecular reactions, and the reaction's industrial applications are limited by harsh conditions. The anionic Fries rearrangement achieves ortho selectivity using strong bases, with applications in various substrates.

What is the mechanism of the Fries rearrangement?

Describe the anionic Fries rearrangement and its advantages.

How does the concept of ortho transfer extend to other groups beyond carbonyls?