33695-97-5Relevant academic research and scientific papers
Facile Formation of o- and p-Tropoquinone Mono- and Bisacetals by Anodic Oxidation of 2,3-, 2,5-, 2,7-, and 4,5-Dimethoxytropones
Mori, Akira,Kubota, Tadahiko,Takeshita, Hitoshi
, p. 3965 - 3972 (1988)
o- and p-Tropoquinone mono- and bisacetals (tetramethoxycycloheptadienones) were prepared from 2,3-, 2,5-, 2,7-, and 4,5-dimethoxytropones by means of anodic oxidations in practical yields.Cerium(IV) salt oxidations of dimethoxytropones afforded a mixture of products i.e., a hydrolysis product and/or a methanol adduct of tropoquinone bisacetals.By treating with sulfuric acid in a mixture of acetic acid and acetic anhydride, 4,4,7,7- and 2,2,7,7-tetramethoxycycloheptadienones gave the Thiele-type reaction products with a high positional selectivity.Similarly, 2-bromo-7-methoxytropone was anodically oxidized to 4,4,7,7-tetramethoxycycloheptadienone and its 2-bromo derivative.The mechanism of the reaction is also discussed in detail.
