112465-74-4Relevant academic research and scientific papers
Direct Formations of o-Tropoquinone Bisacetals from 2,3- and 2,7-Dimethoxytropones and p-Tropoquinone Bisacetals from 2-Bromo-7-methoxytropone by the Anodic Oxidation
Mori, Akira,Kubota, Tadahiko,Kasai, Seishi,Takeshita, Hitoshi
, p. 1931 - 1934 (1987)
Anodic oxidation of 2,7- and 2,3-dimethoxytropones gave the corresponding isomeric o-tropoquinone bisacetals, 2,2,7,7-tetramethoxycyclohepta-3,5-dienone and 2,2,3,3-tetramethoxycyclohepta-4,6-dienone in good yields.By H2SO4-treatment in AcOH-Ac2O, former afforded 4-acetoxy-2,7-dimethoxytropone, 2,5-diacetoxy-7-methoxytropone and 4,5-diacetoxy-3-methoxytropone, latter did no such product.Similar oxidation of 2-bromo-7-methoxytropone gave alternative p-tropoquinone bisacetal derivatives.
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 (2007/10/02)
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.
