Theoretical and Experimental Studies of Regioselectivity in Selenoxide Elimination

Abstract

In order to gain insight into the mechanism of selenoxide elimination, the transition state structures have been determined by applying the ab initio MO method to the elimination for systems having a simplified skeleton, CH 2 (Y)CH(Se(O)CH 3 )CH 3 (Y=OCH 3 , OH, CN and Cl). The calcu- lations show that an allylic alkyl ether and an allylic alcohol should be produced preferentially in the case of Y=OCH 3 and OH, respectively, whereas a vinylic cyanide should be the major product in the case of Y=CN. The chloro-substituted model has given a result most consistent with the methoxysubstituted model