Adducts from quinones and diazoalkanes. Part VI. The formation of a xanthen derivative related to diduroquinone

Abstract

Generated from 2-methyl-1,4-naphthaquinone by way of the diazomethane adduct, the 3-methyl-1,4-naphthaquinon-2-ylmethyl anion reacts with tetramethyl-1,4-benzoquinone giving a xanthen derivative not previously accessible. The spectroscopic properties of this derivative indicate the existence of charge transfer between its isolated chromophores. Oxidation by ferric chloride opens the heterocyclic ring as expected, but reduction by zinc also cleaves a carbon–carbon bond leading to regeneration of the parent phenols. The mass spectral fragmentation of the xanthen is discussed.