DESIGN AND SYNTHESIS OF A TRANSITION-STATE ANALOG FOR THE ENE REACTION BETWEEN MALEIMIDE AND 1-ALKENES

An analog with high similarity to the transition state of the ene reac tion between 1-alkenes and maleimide has been designed and synthesized . The reaction mechanism was studied using propene as a representative 1-alkene. The MP2/6-31G//HF/6-31G* level of accuracy was used for th e ab initio reaction modeling. Although the semiempirical AM1 method d oes not provide accurate reaction energetics, the transition state geo metries were found to be in good agreement with the corresponding HF/6 -3lG structures. The endo transition state of the reaction between 1- butene and maleimide was used for the analog design. The structures fo r both transition state and its putative analogs were optimized using the AM1 method. The transition state and its analogs were compared by rigid body field fitting. The X-ray structure of the analog suggests a reasonable agreement between the computational and the experimental r esults. The analog is now used as a hapten to obtain catalytic antibod ies.