A short and efficient asymmetric synthesis of komaroviquinone

Suto, Yutaka; Kaneko, K.; Yamagiwa, Noriyuki; Iwasaki, Genji

doi:10.1016/j.tetlet.2010.09.110

Cited by 20 publications

(21 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Indeed, the formationo ft he desired product 17 was observed by utilizing severalt ransition metals (entries 6-9, 11,a nd 12). NMR analysis of this compound was difficultd ue to keto-hemiketal tautomerismb etween the open (17)a nd closed form (18), as already observed for as imilarh ydroxy-ketoneb yS uto et al [27] Reactionc onditions involving transition metals without TBHP were also investigated (entries 13-16). [26] The benzylic oxidation product 17 was obtainedi nm oderate yield (31 %) along with the starting material( 13,1 9%).…”

Section: Dioxole Formationmentioning

confidence: 92%

“…[26] The benzylic oxidation product 17 was obtainedi nm oderate yield (31 %) along with the starting material( 13,1 9%). NMR analysis of this compound was difficultd ue to keto-hemiketal tautomerismb etween the open (17)a nd closed form (18), as already observed for as imilarh ydroxy-ketoneb yS uto et al [27] Reactionc onditions involving transition metals without TBHP were also investigated (entries 13-16). [28] However,c ompound 19 (and 20,e ntry 16) or 17 (and 18,e ntries13a nd 15) was produced only in trace amounts.…”

Section: Dioxole Formationmentioning

confidence: 99%

See 1 more Smart Citation

Collective Syntheses of Icetexane Natural Products Based on Biogenetic Hypotheses

Thommen

Neuburger

Gademann

2016

Chemistry A European J

View full text Add to dashboard Cite

A divergent synthesis of 10 icetexane natural products based on a proposed biogenetic cationic ring expansion of a reduced carnosic acid derivative is described. Of these icetexanes, (+)-salvicanol, (-)-cyclocoulterone, (-)-coulterone, (-)-obtusinone D, and (-)-obtusinone E have been synthesized for the first time. In addition, the hypothesis for the non-enzymatic biogenesis of benzo[1,3]dioxole natural products has been experimentally investigated. Additional experimental evidence for the abiotic formation of the methylenedioxy unit is provided, as photolysis of the quinone (+)-komaroviquinone resulted in the formation of the [1,3]dioxole-containing natural product (-)-cyclocoulterone and (+)-komarovispirone.

show abstract

Section: Dioxole Formationmentioning

confidence: 92%

Section: Dioxole Formationmentioning

confidence: 99%

Collective Syntheses of Icetexane Natural Products Based on Biogenetic Hypotheses

Thommen

Neuburger

Gademann

2016

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…Porém, poucos grupos de pesquisa estão estudando rotas sintéticas para a obtenção da komaroviquinona. Padwa e colaboradores realizaram estudos da síntese do esqueleto da komaroviquinona [19,20] e apenas três grupos realizaram a síntese total desta molécula, [21][22][23][24] sendo duas delas enantiosseletivas. [23]…”

Section: -Atividade Tripanossomicida Da Komaroviquinonaunclassified

“…Após a divulgação do trabalho do grupo de Banerjee, Majetich e colaboradores propuseram uma nova rota sintética para a obtenção da (±)komaroviquinona, [22] e também apresentaram a primeira síntese total da (+)komaroviquinona. [23] O Esquema 6 apresenta a proposta de síntese racêmica elaborada pelo grupo O último trabalho que reportou a síntese total da komaroviquinona até o presente momento foi o de Suto e colaboradores [24] , ilustrado no Esquema 8.…”

Section: -Sínteses Totais Da Komaroviquinonaunclassified

“…Nesta proposta, a etapa chave é a reação de abertura de epóxidos por aril-lítios ou aril-magnésios. Com esta estratégia pretende-se contornar os pontos críticos apresentados nas estratégias de síntese já relatadas na literatura, [21][22][23][24] Cabe ressaltar, que esta estratégia permite também a síntese de outros diterpenos icetexanos. Por exemplo, o mesmo trabalho do prof. Burtoloso e colaboradores [26] apresentou um estudo modelo para a obtenção de um análogo do diterpeno brussonol, sendo este obtido em apenas três etapas a contar da etapa de abertura de epóxido (Esquema 12).…”

Section: -Estratégia Sintéticaunclassified

See 1 more Smart Citation

Estudos visando à síntese do tripanossomicida (±)-komaroviquinona

Pereira¹

View full text Add to dashboard Cite

Resumo A doença de Chagas é uma doença endêmica causada pelo protozoário Trypanosoma cruzi que assola cerca de 15 milhões de pessoas na América Latina. Na busca de uma alternativa mais econômica e eficiente para o tratamento desta doença, Kiushi e colaboradores isolaram da planta Darcocephalum komarovi, a komaroviquinona. Após estudos "in vitro" de células humanas contaminadas com tripomastigotos do Trypanosoma cruzi, a komaroviquinona mostrou ser 15 a 300 vezes mais eficiente que os tratamentos atualmente disponíveis. Mesmo com este resultado animador, pouco se tem relatado sobre a síntese da komaroviquinona, existindo apenas 4 rotas sintéticas descritas na literatura, sendo duas delas enantiosseletivas. Baseado neste fato, o presente trabalho visa estudar uma forma de se obter a komaroviquinona de forma rápida e eficaz, utilizando, para tal fim, a estratégia de abertura de epóxidos por um aril-magnésio ou aril-lítio, como etapa chave. Pretende-se com esta estratégia sintetizar a komaroviquinona em 9 etapas, partindo de reagentes disponíveis comercialmente. Cabe ressaltar que esta estratégia possibilita a síntese de outros produtos naturais como o brussonol, que apresentou citotoxidade moderada em células de ovários do inseto Spodoptera frugiperda (Sf9) e células de ovário do mamífero hamster chinês (CHO), além de atividade citotoxicológica às células P388 leucêmicas de camundongo. Alguns resultados promissores foram obtidos como a preparação "one pote" da cetona 2alil-3,3-dimetil-cicloexanona com rendimento na faixa entre 54-65 % e a preparação do respectivo epóxido com rendimento de 89 %. Além destes resultados, a reação de abertura de epóxido se mostrou eficiente quando utilizados organometálicos modelo (disponíveis comercialmente), sendo que os rendimentos foram de 53 % e 62%, dependendo do reagente de Grignard utilizado. Entretanto ainda se faz necessário otimizar as condições reacionais para aplicação dos organometálicos reais, precursores da komaroviquinona e do brussonol.

show abstract

A Formal Synthesis of Komaroviquinone: Use of a Pt‐Catalyzed Hydrative Cyclization Reaction

Piao

Jung

et al. 2016

Asian J Org Chem

View full text Add to dashboard Cite

Af ormal synthesis of komaroviquinone has been accomplished by utilizingt he Pt-catalyzedh ydrative cyclization of an enynal that was easily prepared in ac onvergent manner. The Pt-catalyzed hydrativec yclization reaction afforded the corresponding tricyclic product, which was utilized in the synthesis of ak nown precursor that led to the formation of komaroviquinone through an additional four-step synthesis.Inhabitants of the mountains of Uzbekistan use parts of the perennials emishrubk nown as "buzbosh" to cure inflammatory diseases and hypertony. [1] Severali cetexaned iterpenes have been isolated from buzbosh, among which komaroviquinone has shown the mosts ignificant in vitro trypanocidal activity against epimastigotes of Trypanosoma cruzi,t he causative agent of Chagas' disease in Centrala nd South America, with am inimum lethal concentration( MLC) of 0.4 mm. [2] In addition to komaroviquinone, am inor diterpene that possessedanew spiro-octahydroindene skeleton was also isolated from the same plant and was namedk omarovispirone. Biogenetically, komarovispirone may be derived fromk omaroviquinone througharing-contraction sequence as outlined in Figure 1. [3] Komaroviquinonew as also isolatedf rom the seeds of Hernan-dia ovigeina and hasb een reportedt op lay ap otentialr ole in the developmentofn ew anti-HIV agents. [4] Several groups have been interested in the synthesis of komaroviquinone and related compounds. [5] The characteristic core skeleton of komaroviquinone is a [ 6,7,6] tricycle. Therefore, the discovery of new and efficient synthetic routes to such [6,7,6] tricycles is highly desirable for organic and medicinal chemists. [6] Transition-metal-catalyzed cyclization reactions have been presenteda sahighly attractive methodf or the synthesis of such polycyclic compounds. In 2005, Padwa and coworkers reported the first synthesis of the core skeleton of komaroviquinone by utilizing aRh II -catalyzed intramolecular cyclization reaction. [7] In the same year,B anerjee andc o-workersr eportedt he first total synthesis of (AE)-komaroviquinone. [8] Since then, the Majetich group completed syntheses of komaroviquinone and relatedc ompounds. [9] In 2010, Suto'sg roup accomplished as hort and efficient asymmetrics ynthesis of komaroviquinone from ak nown precursor in only four steps. [10] Well-oriented conjugatede nynals mays erve as versatile substratesf or [6,7,6]-tricyclic skeletons. Such enynals with alkynophilic metal cations are known to form metalÀpyrylium intermediates,w hich undergo cycloaddition reactions with ap endent unsaturated bond. Thus, we successfully performedt he Au-, Rh-, andP t-catalyzed [3+ +2] cycloaddition reactions of o-alkynylbenzaldehyde( S 1 )w ith ap endant unsaturated bond, thereby affording polycycles P 1 , P 2 ,a nd P 3 ,r espectively (Scheme 1). [11] With this diverse range of chemoselectivities in hand, we first prepared ap rospective precursor (1)a nd performed at otal synthesis of faveline methyl ether (5). Disappointingly, Figure 1. Komaroviquinone and komarovis...

show abstract

A short and efficient asymmetric synthesis of komaroviquinone

Cited by 20 publications

References 18 publications

Collective Syntheses of Icetexane Natural Products Based on Biogenetic Hypotheses

Collective Syntheses of Icetexane Natural Products Based on Biogenetic Hypotheses

Estudos visando à síntese do tripanossomicida (±)-komaroviquinona

A Formal Synthesis of Komaroviquinone: Use of a Pt‐Catalyzed Hydrative Cyclization Reaction

Contact Info

Product

Resources

About