Quinones of Benzo- and Dibenzo-Crown Ethers: The preparation of the 1,4-quinones of benzo[15]crown-5 (1), benzo [18]crown-6 (2) and dibenzo[18]crown-6 (3) and their quinols is described. The quinones are obtained by Fremy salt oxidation of the corresponding 3-hydroxybenzo-crown ethers which are readily accessible by a double protective group synthesis from 1,2,3-trihydroxybenzene. The synthetic pathway also provides a general high yield preparation of 2,3-dialkoxyl-1,4-benzoquinones. The new crown ethers are characterised b y 1H- and 13C-N. M. R. as well as U. V. spectroscopy. Non-aqueous redox potentials are determined by cyclic voltammetry. Crystalline complexes of 1 and 2 with various ammonium, alkali, and alkaline earth cations are also described.
Cycloaddition reactions of a crowned p-benzoquinone
作者:Kenji Hayakawa、Keiko Kido、Ken Kanematsu
DOI:10.1039/c39860000268
日期:——
The crowned benzoquinone (1), prepared from pyrogallol in four steps, undergoes Diels–Alder reactions with cyclopentadiene and thebaine to give good yields of the respective adducts containing the crown ether moiety.
Synthesis, metal ion binding, and photochromic properties of benzo- and naphthopyrans annelated by crown ether moieties
作者:Sergey V. Paramonov、Vladimir Lokshin、Artem B. Smolentsev、Evgeni M. Glebov、Valeri V. Korolev、Stepan S. Basok、Konstantin A. Lysenko、Stéphanie Delbaere、Olga A. Fedorova
DOI:10.1016/j.tet.2012.07.029
日期:2012.9
Combining a photochromic chromene with a crown ether moiety results in systems in which photochromism and ionophoric properties could significantly influence each other. In this paper, we report the synthesis of several chromenes annelated by 15(18)-crown-5(6) ethers. The approach involves the building of the photochromic fragment upon the initial crown ether via phenols. The two main routes for chromene
Synthesis of photochromic benzopyrans annulated by 15(18)-crown-5(6) ether
作者:S. V. Paramonov、O. A. Fedorova、V. P. Perevalov、V. Lokshin、V. Khodorkovsky
DOI:10.1007/s11172-008-0339-6
日期:2008.11
The reaction of hydroxy-substituted benzo-15(18)-crown-5(6) ether or benzo-18-crown-6 ether with β-phenylcinnamaldehyde in the presence of titanium tetraethoxide yielded crown-annulated 2,2-diphenylbenzopyrans. The compounds are photochromic, and the spectral characteristics of their colored form are unusual for this class of chromenes.