A Study of Thermal Diels-Alder Reaction of Ethene with Cyclohexa-1,3-diene by Using AM1 Method

UHF/AM1 molecular orbital method has been employed to study the thermal Diels-Alder reaction of ethene with cyclohexa-1,3-diene,The results showed that this reaction is exothermal,and it has two competitive routes;the activation energy of the concerted process is ll2. 667 kJ/mol,and that of the rate-determining step of the biradical pathway is 78.406 kJ/mol,the biradical process has lower activation energy than the concerted one.