Woodward-Hoffmann rules Claisen rearrangement

Carbamimidoyl isothiocyanates on heating easily undergo irreversible isomerization to afford quinazoline-4(3//)-thiones. The reaction comprises two sigmatropic rearrangements (a Claisen rearrangement and a Cope rearrangement) both are allowed according to the Woodward-Hoffmann rules. 

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. 

According to the Woodward-Hoffmann rules, five concerted transition states are possible for the Claisen as well as the closely related Cope rearrangements chair, boat, twist, cross and plane (Table 6) Only the chair and boat TS have to be considered, as twist, cross and plane are antarafacial-anta-rafacial processes and require highly elevated temperatures. For the correct prediction of pro-... 

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