Total synthesis of 7'-desmethylkealiiquinone, 4'-desmethoxykealiiquinone, and 2-deoxykealiiquinone.
Total synthesis of 7'-desmethylkealiiquinone, 4'-desmethoxykealiiquinone, and 2-deoxykealiiquinone.
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DOI：
10.1021/jo4027337
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发表时间：
2014-03-21
期刊：
影响因子：
--
通讯作者：
Lovely CJ
中科院分区：
文献类型：
--
作者：
Lima HM;Sivappa R;Yousufuddin M;Lovely CJ
描述了kealiquinone的咪唑并萘醌核心和相关的白藜芦衍生生物碱的合成方法。多取代苯并咪唑骨架可以通过丙炔酸酯衍生的烯炔的分子内Diels-Alder反应，然后氧化来构建。由此形成的内酯的氧化态的调节允许通过由氰离子催化的邻苯二甲醛衍生物和掩蔽的乙二醛等价物之间的假定的安息香样缩合引入2，3-二羟基苯醌部分。C2-位的氧化可以通过使用漂白剂对咪唑鎓盐进行操作简单的处理来完成，从而产生相应的2-咪唑酮。在用三氟甲磺酸处理后，后期中间体的脱苄基作用受到伴随的O-脱甲基作用的影响，从而形成非天然的7′-脱甲基kealiquinone。评估了其他收尾策略;然而，这些努力并没有导致完成kealiquinone的合成，但确实提供了获得其他密切相关的类似物的途径。
Synthetic approaches to the imidazonaphthoquinone core of kealiiquinone and related Leucetta-derived alkaloids are described. The polysubstituted benzimidazole framework can be constructed through intramolecular Diels–Alder reactions of propiolate-derived enynes followed by oxidation. Adjustment of the oxidation state of the thus formed lactone allows introduction of the 2,3-dihydroxybenzoquinone moiety through a presumed benzoin-like condensation between a phthaldehyde derivative and a masked glyoxal equivalent catalyzed by a cyanide ion. Oxidation of the C2-position can be accomplished through application of an operationally simple treatment of an imidazolium salt with bleach, thus producing the corresponding 2-imidazolone. Debenzylation of a late stage intermediate en route to kealiiquinone was compromised by concomitant O-demethylation upon treatment with triflic acid resulting in the formation of non-natural 7′-desmethylkealiiquinone. Other endgame strategies were evaluated; however, these efforts did not lead to completion of a synthesis of kealiiquinone but did provide access to other closely related analogues.
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影响因子：
1.8
作者：
He, Y;Chen, YZ;Lovely, CJ
通讯作者：
Lovely, CJ
DOI：
10.3891/acta.chem.scand.27-0888
发表时间：
1973-01-01
期刊：
ACTA CHEMICA SCANDINAVICA
影响因子：
--
作者：
LINDGREN, BO;NILSSON, T
通讯作者：
NILSSON, T
影响因子：
5.1
作者：
Fu, X;Barnes, JR;Schmitz, FJ
通讯作者：
Schmitz, FJ
影响因子：
3.6
作者：
Cotterill, Lynsey J.;Harrington, Ross W.;Hall, Michael J.
通讯作者：
Hall, Michael J.
影响因子：
3.2
作者：
He, Yong;Krishnamoorthy, Pasupathy;Lovely, Carl J.
通讯作者：
Lovely, Carl J.