论文信息 - A rapidly reversible degenerate cope rearrangement

A rapidly reversible degenerate cope rearrangement

Abstract The occurrence of a structurally degenerate Cope rearrangement which proceeds rapidly at room temperature is revealed by the examination, at varying temperatures, of the N.M.R. spectrum of bicyclo[5.1.0]octa-2,5-diene (I). This molecule is made by the cyclopropanation of cycloheptatriene in the 3, 4 position according to Gaspar-Roth. Its structure is assigned by virtue of its conversion to bicyclo[5.1.0]octane on catalytic hydrogenation and its failure to absorb U.V. light at λ > 210 mμ. At 225°, its double-bond isomer, bicyclo[5.1.0]octa-2,4-diene (II), rearranges to cycloocta-1,3,5-triene which is subsequently transformed to benzene (and ethylene ?) and a substance tentatively assigned the structure, tricyclo[3.2.1.02,7]oct-3-ene(III). This latter material appears to arise from and be in equilibrium with 5-vinylcyclohexa-1,3-diene (IV) through the relationship of an intramolecular Diels-Alder reaction. The hypothetical tricyclo[3.3.2.04,6]deca-2,7,9-triene (VII) is a uniquely interesting molecule in which individual carbon atoms must circulate freely about the structure quite independently of each other if the Cope rearrangement operates.

W. Doering | W. Roth | W. von E. Doering | W. R. Roth

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