作者:Andreas Merz、Manfred Rauschel
DOI:10.1055/s-1993-25945
日期:——
Crown ethers in which the two methoxy groups of ubiquinone-0 (2,3-dimethoxy-5-methyl-1, 4-benzoquinone) are replaced by oligoethylene glycol bridges have been obtained in five straightforward steps in 35-40% overall yield from 5-methylpyrogallol. A Fremy salt oxidation of a phenolic precursor is used in the final step. The further elaboration of crown ether analogues of ubiquinone-2 was achieved by enol geranylation of cyclopentadiene adducts of the former quinones and subsequent retro-Diels-Alder reaction. The Claisen rearrangement of 2, 2-dimethoxy-5-methylphenyl allyl ethers and related crown ethers affords ortho- and para-allyl-substituted phenols (3: 1) that are oxidized to give bisnorubiquinone derivatives and their ortho- quinone isomers. All new compounds are characterized by high resolution NMR and mass spectrometry.
用五个简单步骤从5-甲基吡咯卡酚中获得了冠醚,其中 ubiquinone-0(2,3-二甲氧基-5-甲基-1,4-苯醌)的两个甲氧基被寡聚乙二醇桥替代,整体产率为35-40%。在最终步骤中采用了Fremy盐氧化酚前体。通过对前述醌的环戊二烯加成物进行烯醇香豆烯基化以及随后的逆Diels-Alder反应,进一步开发了ubiquinone-2的冠醚类似物。2,2-二甲氧基-5-甲基苯基烯丙醚及相关冠醚的Claisen重排产生了ortho和para-烯丙基取代的酚(比例为3:1),随后被氧化生成bisnorubiquinone衍生物及其ortho-醌异构体。所有新化合物均通过高分辨率NMR和质谱进行表征。