Synthesen von Moniliformin, einem Mycotoxin mit Cyclobutendion‐Struktur

Belluš, D.; Fischer, Hans‐Peter; Greuter, Hans; Martin, Pierre

doi:10.1002/hlca.19780610526

Cited by 69 publications

(21 citation statements)

References 110 publications

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“…2a. This correlation can be compared with the first peaks of the PE spectra of A comparison of the 13C data of unsubstituted allene (10) with those of tetraethoxy allene (14) and tetrafluoro allene (12) shows the deshielding of the terminal carbon atoms because of the a-acceptor character of the oxygen and fluorine substituents. On the other hand, the n-donor character of these substituents causes a large shift to higher field for the central carbon atoms of allenes 12 and 14.…”

Section: Creactionsmentioning

confidence: 98%

“Push‐Pull” Substituted Allenes

Saalfrank¹

1985

Israel Journal of Chemistry

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The two prototype "push-pull"-substituted allenes (cyclopropenylidene) (cyclopentadienylidene)methane and (cyclopentadienylidene) (cycloheptatrienylidene)-methane remain unknown. Although (fluoren-9-ylidene) (dibenzo [a,d] cyclohepten-Svylldenejrnethane has been synthesized [3] the spectroscopic data show no significant carbene character. Allene 4 should, however, show considerable carbene character because of the gain in aromatic stabilization on going from allene 4 to carbene s.• A. SynthesisThe difficulties involved in synthesizing and isolating "push-pull"-substituted allenes have two main causes:(1) Normal allene syntheses [4] are totally unsuitable for donor/acceptor substituted allenes. These methods all require the presence of a nucleophile or an electrophile, which then reacts further with the initially formed allene.(2) "Push-pull" allenes are expected to show a strong tendency to dimerize as reactive groups of opposite polarity are part of one and the same molecule.If the non-enohzing ketones 6 are reacted with the

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Section: Creactionsmentioning

confidence: 98%

“Push‐Pull” Substituted Allenes

Saalfrank¹

1985

Israel Journal of Chemistry

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“…1 in einer Ausbeute von 81% [7]. Unsere Suche nach anderen geeigneten [2 + 21-Cycloadditionspartnern fur Methylketen fuhrte nun zu einer Eintopf-Zweistufen-Synthese eines neuen elektronenreichen tetrasubstituierten Athylens, des 1, 1,2-Triathoxy-2-trimethylsilyloxyathylenes (1 l)?).…”

Section: Einleitung -Das Im Jahre 1973 Von Cole Et Al Aus Fusarium unclassified

“…EtO, EtO [7]. Das zu 11 nachstverwandte, silylierte Tetraalkoxyolefin, das 1,2-Diathoxy-1,2-bis(trimethylsilyloxy)-athylen, soll in 64% Ausbeute bei der NatriudKalium-Reduktion von Diathyloxalat in Gegenwart von CISiMe3 entstehen [14].…”

Section: Schemaunclassified

“…Bedingungen veroffentlicht worden. Eine mogliche Erklarung fur die niedrige Ausbeute von 9 liegt in der asymmetrischen Substitution in II; das Methylketen kann mit 11 nun zwei isomere 1,4-dipolare Zwischenprodukte 12 oder 13 (zu einem Vorlaufer der Quadratsaure) unerwartet auf 38% gestiegen war [7], haben wir auch untersucht, ob eine analoge Reaktion von 1,l -Dichlor-1 -propen (26) mit 25 zu einem fur die Hydrolyse zu 9 geeigneten (1 : 1)-Photoaddukt fuhren wiirde. In der Tat entstand bei der Acetophenon-sensibilisierten Bestrahlung von 25 in Gegenwart von 26 ein komplexes Gemisch, dessen Auftrennung durch Saulenchromatographie ein Isomerengemisch 27 im Verhaltnis von 5,8 : 4,2 (aus 'H-NMR.)…”

Section: Schemaunclassified

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Synthesen von 3‐Hydroxy‐4‐methyl‐3‐cyclobuten‐1,2‐dion (Methylmoniliformin)

Belluš

Martin

Sauter

et al. 1980

Helvetica Chimica Acta

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Syntheses of 3-Hydroxy-4-methyl-3-cyclobutene-1,2-dione (Methylmoniliformin) SummaryNew routes to 3-hydroxy-4-methyl-3-cyclobutene-1,2-dione (9), the lowest homologue of the mycotoxine moniliformin are described. A common feature of all pathways is the synthesis of methylcyclobutanes having the oxidation level 6. Precursors, which are easily transformed to 9 by acid catalyzed hydrolysis, include [2 + 21-cycloadducts of in situ generated methyl ketene to tetraethoxyethylene and [2 + 21-photocycloadducts of dichlorovinylenecarbonate with 1,l-dichloro-1-propene. The acid hydrolysis of [2 + 21-cycloadducts of chlorotrifluoroethylene to N, N-diethyl-1-propynylamine yields the diethylamide of 9 (= 22) in 50% overall yield. In addition, a convenient one-pot-two-steps synthesis of a new electronrich ethylene, 1, 1 ,2-triethoxy-2-trimethylsilyloxy-ethylene (ll), is described.

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“…The free acid is a strong acid. In the literature its pK a value varies [10] from 0.0±0.05 [11] to 1.7 [12,13]. Thus, the chemical behaviour of the relatively small semisquaric anion (M=97) can be assumed to be similar to that of inorganic anions.…”

Section: Introductionmentioning

confidence: 99%

Determination of moniliformin in maize by ion chromatography

Kandler¹,

Nadubinská

Parich³

et al. 2002

Analytical and Bioanalytical Chemistry

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An ion chromatographic method for the determination of the mycotoxin moniliformin in maize was developed. The method contains a fast and simple clean-up procedure, which allows high volume sample injection. No further pre-concentration step is required. The limit of quantification was estimated to be 0.12 mg/kg moniliformin in maize. In contrast to the two previously published ion chromatographic methods, the moniliformin peak is base line separated and occurs in a region of a smooth base line in the ion chromatogram. The newly developed method showed a recovery through the whole analytical procedure of 97+/-3.5 %, whereas most previously described analytical methods had recoveries in the 70% range.

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Synthesen von Moniliformin, einem Mycotoxin mit Cyclobutendion‐Struktur

Cited by 69 publications

References 110 publications

“Push‐Pull” Substituted Allenes

“Push‐Pull” Substituted Allenes

Synthesen von 3‐Hydroxy‐4‐methyl‐3‐cyclobuten‐1,2‐dion (Methylmoniliformin)

Determination of moniliformin in maize by ion chromatography

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