Total Synthesis and Elucidation of the Absolute Configuration of the Diterpene Tonantzitlolone

Jasper, Christian; Wittenberg, Rüdiger; Quitschalle, Monika; Jakupovic, Jasmin; Kirschning, Andreas

doi:10.1021/ol047559e

Cited by 40 publications

(22 citation statements)

References 24 publications

(14 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…21 Do extrato hexânico do lenho da raiz foram isolados e identificados o diterpeno macrocíclico denominado tonantzitlolona (5) [22][23][24] e o triterpenóide lupeol (6). 25 O diterpeno macrocíclico (5), também, foi isolado do extrato hexânico da casca da raiz de S. macrocarpa (Figura 1).…”

Section: Resultsunclassified

“…150-151 o C, [α] D 25 +134 o (c 0,25; CHCl 3 ), que foi identificado como o diterpeno macrocíclico denominado tonantzitlolona (5). [22][23][24] O extrato hexânico do lenho da raiz (6,5 g) foi submetido à cromatografia em coluna, utilizando os eluentes hexano, clorofórmio, acetato de etila e metanol, puros ou em misturas binárias, sendo coletadas 46 frações de 25 mL. A fração 21-27 (hexano/clorofórmio 5/5) (1,6 g) foi submetida a outra coluna cromatográfica fornecendo a sub-fração 10-43 (hexano/acetato de etila 9/1) (577,5 mg), que foi purificada em coluna de gel de sílica, coletando-se frações de 7 mL, obtendo-se a fração 4-8 (hexano/clorofórmio 6/4) (26,5 mg) de um sólido branco, p.f.…”

Section: Parte Experimental Procedimentos Experimentais Geraisunclassified

See 1 more Smart Citation

Constituintes químicos de Sebastiania macrocarpa Muell. Arg. (Euphorbiaceae)

Lima¹,

Lima²,

Arriaga³

et al. 2009

Quím. Nova

View full text Add to dashboard Cite

Recebido em 26/2/08; aceito em 10/9/08; publicado na web em 2/2/09 CHEMICAL CONSTITUENTS FROM Sebastiania macrocarpa MUELL. ARG. (EUPHORBIACEAE). The chemical investigation of the methanolic extract of the aerial part of Sebastiania macrocarpa allowed the isolation of the mixture of steroids β-sitosterol and stigmasterol, gallic acid, and scopoletin. The hexane extract of the roots allowed the isolation of the triterpene lupeol and of the macrociclic diterpene (+)-tonantzitlolone. The structures of all compounds isolated were identified on the basis of their spectral data and by comparison of their spectral data with values described in the literature. This is the first report involving the chemical investigation of this species.

show abstract

Section: Resultsunclassified

Section: Parte Experimental Procedimentos Experimentais Geraisunclassified

Constituintes químicos de Sebastiania macrocarpa Muell. Arg. (Euphorbiaceae)

Lima¹,

Lima²,

Arriaga³

et al. 2009

Quím. Nova

View full text Add to dashboard Cite

show abstract

“…Several strategies to construct the macrocyclic diterpene tonantzitlolone (157) via RCM have been accomplished [68]. While the C1-C2 double bond could not be formed probably due to steric congestion created by the three allylic methyl groups present in the starting material, macrocycle 156 was eventually obtained from 155 with high E-selectivity due to less congested olefins (Scheme 5.36).…”

Section: Diterpenoidsmentioning

confidence: 99%

Synthesis of Natural Products Containing Macrocycles by Alkene Ring‐Closing Metathesis

Gradillas¹,

Pérez‐Castells²

2010

Metathesis in Natural Product Synthesis

View full text Add to dashboard Cite

IntroductionThe impact of metathesis in modern synthetic chemistry is evidenced by the number of publications and reviews that have appeared in the last decade, some of them covering the specific field of macrocyclization in natural product synthesis [1]. It is therefore difficult not to repeat the reports done by other authors or duplicate their critical views on the chemistry. This chapter is exclusively devoted to the total syntheses of natural bioactive macrocycles involving diene and the diene-ene metathesis, and focuses on the reaction conditions used in the macrocyclization key step and on the stereochemical outcome of the reaction. As we shall see, the choice of the catalyst, solvent, temperature, concentration, and reaction time is crucial in these transformations. In addition, we show how subtle variations on the structure of the substrate lead to modifications in the conformational organization of the molecule, which are critical for the success of ring-closing metathesis (RCM). In particular, the substitution pattern, the steric hindrance of the substituents, the ring size to be formed, and the presence of coordinating heteroatoms are particularly important as they have an important influence on the outcome of the reaction. This chapter has been organized around the various families of natural products in order to compare the reaction conditions for compounds bearing structural similarities. We have deliberately decided to reveal only the information regarding the metathesis step and thus not disclose other details of the syntheses.Synthetic efforts toward macrocycles are often laborious and unpractical. The classical strategies involved are macrolactonizations, macrolactamizations, and macroaldolizations. The macrocyclization approach encounters several problems including the competition between the desired intramolecular reaction and intermolecular processes, which result in the formation of polymers. RCM has the advantage of being compatible with a wide variety of functional groups and forming double bonds that can eventually be converted into other functionalities. The main disadvantages are the control of the stereochemistry of the newly formed double bond and the optimization of the yield. On the other hand, the concomitant loss of ethylene makes this reaction highly atom economical and entropically Metathesis in Natural Product Synthesis: Strategies, Substrates and Catalysts. Edited by

show abstract

“…Kirschning e colaboradores empreenderam a síntese enantiosseletiva deste diterpeno macrocíclico natural de 15 membros, isolado da planta mexicana Stillingia sanguinolenta, com uma ambição dupla: realizar a primeira síntese total deste macrociclo complexo e estabelecer a configuração absoluta, ainda não determinada 50 . Numa primeira abordagem, os autores testaram o fechamento ao nível da ligação dupla C1-C2, aparentemente o mais lógico.…”

Section: Influência Dos Substituintes E Dos Grupos Protetoresunclassified

Metátese de olefinas aplicada ao fechamento de anéis: uma ferramenta poderosa para a síntese de macrociclos naturais

Santos¹,

Kaiser²,

Férézou³

2008

Quím. Nova

View full text Add to dashboard Cite

Recebido em 7/3/07; aceito em 30/8/07; publicado na web em 26/2/08 RING-CLOSING OLEFIN METATHESIS: A POWERFUL TOOL FOR THE SYNTHESIS OF NATURAL MACROCYCLES. For a quarter of a century, metathesis has become indispensable for the synthesis of natural and non-natural products, particularly of biologically active compounds. This review illustrates through a maximum of appropriate examples the power and the versatility of the metathesis ring-closure (RCM) reaction as a key ring-closure methodology for the synthesis of natural macrocycles. Its high functional group compatibility as well as the possibility of further transformations makes this reaction a powerful tool in the cases where the structural framework and function requirements are difficult to meet.

show abstract

Total Synthesis and Elucidation of the Absolute Configuration of the Diterpene Tonantzitlolone

Cited by 40 publications

References 24 publications

Constituintes químicos de Sebastiania macrocarpa Muell. Arg. (Euphorbiaceae)

Constituintes químicos de Sebastiania macrocarpa Muell. Arg. (Euphorbiaceae)

Synthesis of Natural Products Containing Macrocycles by Alkene Ring‐Closing Metathesis

Metátese de olefinas aplicada ao fechamento de anéis: uma ferramenta poderosa para a síntese de macrociclos naturais

Contact Info

Product

Resources

About