Chinone von Benzo- und Dibenzokronenethern

Article abstract of DOI:10.1055/s-1985-34140

The preparation of the 1,4-quinones of benzo<15>crown-5 (1), benzo<18>crown-6 (2), and dibenzo<18>crown-6 (3) and their quinols is described.The quinones are obtained by Fremy salt oxidation of the corresponding 3-hydroxybenzo-crown ethers which are readily accessible by a double protective group synthesis from 1,2,3-trihydroxybenzene.The synthetic pathway also provides a general high yield preparation of 2,3-dialkoxy-1,4-benzoquinones.The new crown ethers are characterised by 1H- and 13C-N.M.R. as well as U.V. spectroscopy.Non-aqueous redox potentials aredetermined by cyclic voltammetry.Crystalline complexes of 1 and 2 with various ammonium, alkali, and alkaline earth cations are also described.