Thermal concerted reactions Claisen rearrangement

Problem 4.17. A small amount of 4-allylphenol is often obtained from the Claisen rearrangement of allyl phenyl ether. Draw a concerted mechanism for this reaction, name the mechanism, and determine whether the suprafacial-suprafacial rearrangement is thermally allowed or disallowed by the Woodward-Hoffmann rules. If it is not allowed, draw a multistep mechanism for the reaction. 

A number of interesting and useful organic reactions involve isomerizations of substances having one or more carbon-carbon double bonds. This chapter deals with the kinetics of reactions of alkenes, cycloalkenes and substituted alkenes which involve migration of carbon-carbon double bonds, with or without structural alteration of the carbon skeleton of the starting materials. These reactions include prototropic and anionotropic rearrangements, several concerted unimolecular isomerizations such as the Cope and Claisen rearrangements, and a number of non-concerted thermal isomerization reactions. 

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