Baker–Venkataraman rearrangement

The Baker–Venkataraman rearrangement is the chemical reaction of 2-acetoxyacetophenones with base to form 1,3-diketones.

This rearrangement reaction proceeds via enolate formation followed by acyl transfer. It is named after the scientists Wilson Baker and Krishnasami Venkataraman.

The Baker–Venkataraman rearrangement is often used to synthesize chromones and flavones.

A base abstracts the hydrogen atom alpha to the aromatic ketone, forming an enolate. Then, the enolate attacks the ester carbonyl to form a cyclic alkoxide. The cyclic intermediate is opened up to form a more stable phenolate, which is protonated during acidic work-up to give the desired product.

...
Wikipedia