Stereospecificity of electrocyclic reactions

A few months after the communication by Woodward and Hoffmann, H. C. Longuet-Higgins and E. W. Abrahamson 3> suggested a different approach to the problem of stereospecificity of electrocyclic reactions, based on correlation diagrams between the orbitals, the electron configurations, and the states of the reactant and the product. 

Orbital Symmetry Basis for the Stereospecificity of Electrocyclic Reactions... 

The method was first used by Roald Hoffmann, who developed, with R. B. Woodward, the rnles for elucidating reaction mechanisms (the Woodward-Hoffmann rnles). These rnles explain the stereospecifity of electrocyclic reactions under thermal and photochemical conditions. The rules illustrated elegantly and simply the power of molecnlar orbital theory to experimental chemists. 

The parallelism between Clar s intuitive notion of aromatic sextets, migrating sextets, and anpty (of sextets) rings and the relative magnitudes of the numerical ring bond orders is so complete that there is not a single exception. So, in this respect, this theory is comparable with the Woodward-Hoffmann rules [28-31] initially formulated to explain the impressive stereospecificity of electrocyclic reactions under thermal and photochemical control. One lengthy review article on Woodward-Hoffmann rules ends with Exceptions None." The same is the case with our numerical characterization of k aromatic sextets with RBO. 

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See also in sourсe #XX -- [ ]

See also in sourсe #XX -- [ ]

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