The Thermal Addition Reactions of Cycloheptatriene with Aromatic<i>p</i>-Quinones
作者:Akira Mori、Hiroaki Mametsuka、Hitoshi Takeshita
DOI:10.1246/bcsj.58.2072
日期:1985.7
Thermal addition reactions of cycloheptatriene with several aromatic p-quinones gave the Diels-Alder adducts as minor products; the most characteristic feature was the formation of the vic-ditropylation products. The mechanism of their formation was clarified to be a sequential ene-reaction and dehydrogenation by means of chemical conversion from the isolated intermediates. Several new other additions
Synthesis and Electrochemical Properties of 3-(3,6-Dioxo-1,4-cyclohexadienyl)methyl-<i>p</i>-tropoquinone. Analysis of a Four-Electron Redox System by Cyclic Voltammetry
作者:Akira Mori、Yasutomo Goto、Hitoshi Takeshita
DOI:10.1246/bcsj.60.2497
日期:1987.7
was prepared from 2,5-bis(arylmethoxy)tropone by consecutive reaction, a homolytic rearrangement, subsequent debenzylation, and a DDQ–dehydrogenation. According to cyclic voltammetry, this four-electron redox system was operative, in sharp contrast to the case of the benzenoid bisquinones, via four successive one-electron transfer processes. Two other tropolone derivatives carrying p-benzoquinone segment
obtained at all, but with 2-methoxyfuran, a double Michael adduct was isolated from the reaction under the atmospheric pressure, and its structure was elucidated mainly by 1H NMR analysis. With 3,4-dimethoxyfuran, an exo-1 : 1-adduct and its further reacted 2 : 1-adduct were isolated.
The Cerium(IV) Ammonium Nitrate Oxidation of 5-Hydroxy-2-methoxytropone to Bitropolonyl Derivatives and One-Step Synthesis of 3-Methoxy-<i>p</i>-tropoquinone
作者:Akira Mori、Yasutoshi Isayama、Hitoshi Takeshita
DOI:10.1246/bcsj.59.511
日期:1986.2
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.
与苯类等价物对甲氧基苯酚不同,硝酸铈 (IV) 铵 (CAN) 氧化 5-羟基-2-甲氧托酮产生 C-C 偶联产物。另一方面,通过硝酸铊 (III) (TTN) 或 CAN 在 50 °C 下,5-羟基托酚酮,一种游离的托酚酮,与对托苯醌和 8-氧杂双环酮一起得到 3-甲氧基-对-托苯醌[3.2。 1]辛烯酮衍生物,但没有二聚产物。
Spectral Evidences for the J-Aggregate Formation of a Non-Benzenoid Aromatic Dye, Dicyclohepta[5,6:<i>b</i>]pyrazino[2,3-<i>g</i>]quinoxaline-3,11-dione
The planar and symmetrically conjugated π-system, dicyclohepta[5,6:b]pyrazino[2,3-g]quinoxaline-3,11-dione, showed a narrow and intense absorption band and resonance fluorescence in cone H2SO4 solutions as low as 10−7 M. These observations show the formation of the J-aggregate. A remarkable solvatochromism was also noticed in organic solvents (476 nm in CHCl3 and 547 nm in DMF).