The Witkop–Winterfeldt oxidation converts tetrahydropyridoindoles into pyrroloquinolones and cinnolines by an unprecedented scaffold rearrangement
摘要:
The Fischer indole reaction between phenylhydrazines and tosyl-4-piperidone furnishes tetrahydropyrido[4,3-b]indoles. In a Witkop-Winterfeldt-oxidation using ozone such indole derivatives are converted into medium-sized dicarbonyl ring systems, which cyclize to pyrroloquinolones. A detailed study of the reaction intermediates and the characterization of a cinnoline betaine side product formed by an unprecedented ring closure mechanism are reported. (C) 2010 Elsevier Ltd. All rights reserved.
The Witkop–Winterfeldt oxidation converts tetrahydropyridoindoles into pyrroloquinolones and cinnolines by an unprecedented scaffold rearrangement
摘要:
The Fischer indole reaction between phenylhydrazines and tosyl-4-piperidone furnishes tetrahydropyrido[4,3-b]indoles. In a Witkop-Winterfeldt-oxidation using ozone such indole derivatives are converted into medium-sized dicarbonyl ring systems, which cyclize to pyrroloquinolones. A detailed study of the reaction intermediates and the characterization of a cinnoline betaine side product formed by an unprecedented ring closure mechanism are reported. (C) 2010 Elsevier Ltd. All rights reserved.