A Novel Dieckmann-Type Cyclization, the Final Step of the Synthesis of a Carbacephem Derivative

Neyer, Gebhard; Ugi, Ivar

doi:10.1055/s-1991-26563

Cited by 12 publications

(4 citation statements)

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“…In a similar fashion, carbapenems, [195] carbacephems, [109,196] carbacephams, [197] and cephalosporin derivatives were synAngew. Chem.…”

Section: Cyclic Variants Of the U-mcrs With Bifunctional Parent Compomentioning

confidence: 95%

“…[180] Apart from cysteine, all known natural and many unnatural a-amino acids can undergo this reaction with aldehydes, mostly with good to excellent yields. [181] a-Amino acids with nucleophilic side groups, such as lysine (196) and ornithine, react intramolecularly via the elusive cyclic intermediate (197 in the case of 196), affording the corresponding seven- (198) or sixmembered a-aminolactam. [182] Whereas serine and threonine are transformed intermolecularly to the corresponding iminodicarboxylic acid derivatives without participation of the hydroxy function, homoserine (199) as the a-amino acid component leads to the a-amino-g-lactam 200 in the solvent trifluoroethanol.…”

Section: Reviewsmentioning

confidence: 99%

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Multicomponent Reactions with Isocyanides

Dömling

Ugi

2000

Angew. Chem. Int. Ed.

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3,976

1,635

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Multicomponent reactions (MCRs) are fundamentally different from two‐component reactions in several aspects. Among the MCRs, those with isocyanides have developed into popular organic‐chemical reactions in the pharmaceutical industry for the preparation of compound libraries of low‐molecular druglike compounds. With a small set of starting materials, very large libraries can be built up within a short time, which can then be used for research on medicinal substances. Due to the intensive research of the last few years, many new backbone types have become accessible. MCRs are also increasingly being employed in the total synthesis of natural products. MCRs and especially MCRs with isocyanides offer many opportunities to attain new reactions and basic structures. However, this requires that the chemist learns the “language” of MCRs, something that this review wishes to stimulate.

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“…In a similar fashion, carbapenems, [195] carbacephems, [109,196] carbacephams, [197] and cephalosporin derivatives were synAngew. Chem.…”

Section: Cyclic Variants Of the U-mcrs With Bifunctional Parent Compomentioning

confidence: 95%

Section: Reviewsmentioning

confidence: 99%

Multicomponent Reactions with Isocyanides

Dömling

Ugi

2000

Angew. Chem. Int. Ed.

Self Cite

3,976

1,635

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“…Die Varianten 1 (cyclische Imine), 2 (w-Oxocarbonsäuren), 3 (w-Aminocarbonsäuren) und 5 (w-Isocyancarbonsäu-ren) wurden bereits realisiert. ¾hnlich konnten Carbapeneme, [195] Carbacepheme, [109,196] Carbacephame [197] und Cephalosporinderivate durch U-4CR hergestellt werden. Bemerkenswerterweise konnten Hatanaka et al die exocyclische Amidbindung von b-Lactamen mit PCl 5 /MeOH hydrolysieren, ohne dass der b-Lactamring des Oxacepham gespalten wurde.…”

Section: Mit Bifunktionellen Ausgangsverbindungen Zu Cyclischen Variaunclassified

Multikomponentenreaktionen mit Isocyaniden

2000

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EinleitungOrganisch-chemische Synthesen haben einen hohen Grad an Kunstfertigkeit erlangt. Kaum ein komplizierter Naturstoff entzieht sich einer vielstufigen Totalsynthese. Dabei werden die Zielmoleküle oft mehr divergent als konvergent, also sequentiell, entsprechend ihrer Komplexität in vielen Schritten synthetisiert. Der Fortschritt in der Totalsynthese von Naturstoffen der vergangenen Jahrzehnte lässt sich beim Vergleich der Strychninsynthese von Woodward mit neueren Synthesen erkennen. [1] Er beruht z. T. auf der Optimierung von Syntheseoperationen und Reaktionen. Metallorganische Varianten klassischer Reaktionen sind häufig diastereo-, enantio-, regio-und/oder chemoselektiver und liefern die Produkte oft in besseren Ausbeuten. Verbesserte analytische sowie Trennmethoden tragen zu effizienteren Syntheseschritten bei. Während Woodward für seine 28-stufige Strychninsynthese 6 Â 10 À5 % Gesamtausbeute erhielt, konnten die Gruppen von Magnus, Overman, Kuehn und Rawal diese komplexe Verbindung in weniger Syntheseschritten und in 10 3 -bis 10 4 -mal höherer Gesamtausbeute herstellen.

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“…Intramolecular diester cyclization to give cyclic β‐Keto esters is commonly known as the Dieckmann condensation [10]. An enormous number of examples for the construction of carbon systems with varying ring size using this reaction have been reported [11–24]. Some of the recent reports focus on the synthesis of pulvinones [25], indolizidines [26], mycophenloic acid [27], and rutaecarpine [28].…”

Section: Introductionmentioning

confidence: 99%

Novel synthesis of 1,2,4‐triazolophanes and 1,3,4‐oxadiazolophanes: A dieckmann condensation approach

Chande

Sajithkumar

Mondkar

et al. 2011

Journal of Heterocyclic Chem

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The Dieckmann condensation has been used for the first time for the syntheses of novel 1,2,4-triazolophanes and 1,3,4-oxadiazolophanes. The bis-1,3,4-oxadiazol-2-thiols 1a and 1b were reacted with ethyl bromoacetate to give the diesters 2a and 2b. Diesters 2a and 2b were treated under dry conditions with sodium methoxide in methanol to afford desired symmetrical 1,3,4-oxadiazolophanes 3a and 3b. Similarly, diesters of macrocycle precursors containing 1,2,4-triazole moiety, that is, 6a, 6b, 10, 13a, 13b, and 13c were synthesized from 5a, 5b, 9, 12a, 12b, and 12c, respectively. Dieckmann condensation of these diesters afforded symmetrical ketones 7a, 7b, 11, 14a, 14b, and 14c. Extrusion of CO 2 was observed after in situ hydrolysis of the conventional Dieckmann product during neutralization by dilute mineral acids to afford highly symmetrical ketone in good yields. Further, the ketones 14a, 14b, and 14c were converted into their respective thiones by the reaction with Lawesson's reagent. All the products were synthesized with good yields, and structures were confirmed by various spectroscopic tools and elemental analyses.

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A Novel Dieckmann-Type Cyclization, the Final Step of the Synthesis of a Carbacephem Derivative

Cited by 12 publications

References 0 publications

Multicomponent Reactions with Isocyanides

Multicomponent Reactions with Isocyanides

Multikomponentenreaktionen mit Isocyaniden

Novel synthesis of 1,2,4‐triazolophanes and 1,3,4‐oxadiazolophanes: A dieckmann condensation approach

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