Propose a mechanism for the following Cope rearrangement.

Question: Describe the mechanism of the Cope rearrangement in a 1,5-diene system. Answer: The mechanism of the Cope rearrangement in a 1,5-diene system involves a [3,3]-sigmatropic shift with a concerted movement of electron pairs. This leads to the formation of a new double bond between the second and sixth atom, while breaking the original double bonds between the first and second atom, and between the fourth and fifth atom. Simultaneously, new single bonds are formed between the first and fourth atom, and between the fifth and sixth atom. The transition state during this rearrangement is stabilized by the delocalization of electron pairs over the six atoms in the 1,5-diene system. The final product has a new double bond between the second and sixth atom, and new single bonds between the first and fourth atom, and between the fifth and sixth atom.