Oxy-Cope Rearrangement

The Cope rearrangement of 1,5-hexadienes with a hydroxy group at the 3-position is called the oxy-Cope rearrangement. The product after the rearrangement is an enol. The enol irreversibly turns into a carbonyl group, which is considered to be the driving force of this reaction. Furthermore, an alternative method has been reported in which the reaction rate is drastically improved by converting the hydroxyl group into an alkoxide with potassium hydride or sodium hydride. Thanks to this method, this reaction can be operated below room temperature while the conventional method requires heat. Since then, the oxy-Cope rearrangement has been widely used, and Paquette’s group has often reported the total syntheses of natural products using this reaction as a key step.