Are the 1,4 - Dihydropyrazines Antiaromatic? Ab Initio Study of 1,4 - Dihydropyrazines and Their Tetrahydro Analogues.

Abstract

A set of twenty molecules containing 1,4-dihydro - or tetrahydropyrazine ring was calculated using ab initio methods. On the basis of structural, electronic and energy arguments it is proposed to classify 1,4 - dihydropyrazines as nonaromatic compounds.