For 10 points, name this reaction that produces an unsaturated carbonyl compound from an allyl vinyl ether.
An enzyme called LynF attaches prenyl groups to tyrosine via an intermediate that spontaneously undergoes this reaction. That aromatic version of this reaction is then followed by re-aromatization, in this case reforming the tyrosine hydroxyl group. This reaction also occurs in the first committed step in synthesis of tyrosine and phenylalanine, the conversion of chorismate to prephenate. Electron donating groups on the (*) vinyl C-1 increase the reaction rate, which led to variations co-named for Eschenmoser and Ireland. This reaction typically passes through a chair transition state, and the presence of a bulky substituent at C-4 leads to formation of E  alkenes. This typically non-catalyzed reaction follows a similar mechanism to the Cope rearrangement, and both are [3,3]-sigmatropic reactions.  For 10 points, name this reaction that produces an unsaturated carbonyl compound from an allyl vinyl ether.
An enzyme called LynF attaches prenyl groups to tyrosine via an intermediate that spontaneously undergoes this reaction.
Claisen Rearrangement