Auwers synthesis
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The Auwers synthesis is a series of organic reactions forming a flavonol from a coumarone. This reaction was first reported by Karl von Auwers in 1908.[1][2][3][4]
The first step in this procedure is an acid catalyzed aldol condensation between benzaldehyde and a 3-oxypentanone to an o-hydroxychalcone. Bromination of the alkene group gives a dibromo-adduct which rearranges to the flavonol by reaction with potassium hydroxide.
[edit] Mechanism
A possible mechanism for the rearrangement step is shown below:
