Thermal isomerization of 1,5-diene into regio-specific 1,5-diene is known as cope rearrangement. This rearrangement is generally reversible in nature and is key in the synthesis of complex natural products such as alkaloids, carbohydrates, etc. in organic chemistry.   Mechanism of Cope and Claisen rearrangements are very similar.   Anionic oxy-cope rearrangement is the reaction in which OH group (hydroxyl group) is present in the structure as shown below,   Oxy-cope rearrangement is generally irreversible, and the reaction can be speeded up by using potassium hydride (KH).