The first and the second half-wave potentials of p-tropoquinones measured by CV are linear to the Hammett’s Σσp and Σσm, respectively. Their smaller electrostatic repulsion than p-benzoquinones can be attributable to the characteristic three carbonyl system.

Durch Verwendung der Oxidationsmethode A) (nicht anwendbar auf freie Tropolonderivate) lassen sich die Z‐Alkoxy‐S‐hydroxytropone (I) und (VI) in guter bis sehr guter Ausb. in die . Mono‐ und Diacetale von Tropochinonen überführen.

Unlike the benzenoid equivalent, p-methoxyphenol, the cerium(IV) ammonium nitrate (CAN)-oxidation of 5-hydroxy-2-methoxytropone gave C–C coupling products. On the other hand, either by thallium(III) nitrate (TTN) or CAN at 50 °C, 5-hydroxytropolone, a free tropolone, gave 3-methoxy-p-tropoquinone together with p-tropoquinone and 8-oxabicyclo[3.2.1]octenone derivatives, but no dimeric product.

The thallium(III) nitrate-oxidation of 2-alkoxy-5-hydroxytropones gave, in good yields, the mono- and diacetals of tropoquinones, which can be used for the introduction of oxygen functions to the seven-membered nucleus and preparation of the substituted tropoquinones. An improved synthesis of 4-methyl-p-tropoquinone or 4-methoxy-p-tropoquinone was accomplished.

Ce(IV) oxidizes the tropone (Ia) in absolute methanol to give predominantly C ‐Ccoupling products [(11), (V), and (VI), the bis‐monoacetal of the hitherto unknown bisquinone (VII)], whereas no dimeric products are obtainable from (Ib) by Ce(IV) or TKNOJ), oxidation.