ON THE QUESTION OF SELECTIVE PROTOCOL FOR THE PREPARATION OF JUGLONE <i>via</i> (4+2) CYCLOADDITION INVOLVING 3-HYDROXYPYRIDAZINE: DFT MECHANISTIC STUDY

Abstract

The possibility of preparation of juglone via Diels–Alder reaction of 3-hydroxypyridazine and 2-nitroquinone was analyzed on the basis of DFT computational study. It was found that key stage of the proposed transformation is head-to-head, polar cycloaddition process, which is realized without formation of zwitterionic intermediate. Further transformations of the intermediate exhibit nature of pseudocyclic reactions with nonconcerted reorganization of the electron density.