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Cerium(III) Chloride–Catalyzed One-Pot Synthesis of Tetrahydrobenzo[b]pyrans [PDF]
Synthetic Communications, 2009 Efficient one-pot synthesis of 4H-benzo[b]pyrans via a three-component cyclocondensation of aryl aldehydes, malononitrile, and dimedone has been reported using CeCl3·7H2O as ...
Sudhakar, K. +4 more
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Chemische Berichte, 1970
AbstractWie am Beispiel von 4‐Hydroxy‐cumarin und Barbitursäure gezeigt werden konnte, gehen diese β‐Dicarbonylverbindungen mit Aldehyden und Phenylacetylen keine Dreikohlenstoff‐kondensation ein. Es entstehen kondensierte Pyrane durch 1.4‐Addition des Phenylacetylens an das ungesättigte Zwischenprodukt aus Aldehyd und Dicarbonylverbindung.
Karl Ernst Schulte +2 more
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AbstractWie am Beispiel von 4‐Hydroxy‐cumarin und Barbitursäure gezeigt werden konnte, gehen diese β‐Dicarbonylverbindungen mit Aldehyden und Phenylacetylen keine Dreikohlenstoff‐kondensation ein. Es entstehen kondensierte Pyrane durch 1.4‐Addition des Phenylacetylens an das ungesättigte Zwischenprodukt aus Aldehyd und Dicarbonylverbindung.
Karl Ernst Schulte +2 more
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Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1976
1. It was established that the hydrogen atom in sym-octahydroxanthene was a high hydride mobility. 2. The disproportionation of sym-octahydroxanthene was effected using acids and a mechanism was proposed for this reaction. 3. A mechanism was proposed for the formation of pyrylium salts from 1,5-diketones.
V. G. Kharchenko +4 more
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1. It was established that the hydrogen atom in sym-octahydroxanthene was a high hydride mobility. 2. The disproportionation of sym-octahydroxanthene was effected using acids and a mechanism was proposed for this reaction. 3. A mechanism was proposed for the formation of pyrylium salts from 1,5-diketones.
V. G. Kharchenko +4 more
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Chemistry of Heterocyclic Compounds, 1983
Data on the chemistry of monocyclic, unsaturated, six-membered, oxygen-containing heterocycles, viz., 4H-pyrans, are correlated and systematized for the first time. The methods for their synthesis, their transformations, and spectroscopic data for them are discussed. The interest in these compounds, which has increased recently, is due to the fact that
O. V. Drygina, A. D. Garnovskii
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Data on the chemistry of monocyclic, unsaturated, six-membered, oxygen-containing heterocycles, viz., 4H-pyrans, are correlated and systematized for the first time. The methods for their synthesis, their transformations, and spectroscopic data for them are discussed. The interest in these compounds, which has increased recently, is due to the fact that
O. V. Drygina, A. D. Garnovskii
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ChemInform Abstract: PHOTOCHEMICAL REARRANGEMENT OF 4H‐PYRANS AND OF DIENONES TO 2H‐PYRANS
Chemischer Informationsdienst, 1980AbstractDie Photoreaktivität der 4H‐Pyrane (I) wurde mit Hilfe von Fluoreszenz‐ und Phosphoreszenz‐Messungen, Desaktivierungsmessungen für den Singulettzustand und durch Bestimmung von Quantenausb.
F. FOURNIER +3 more
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Pyrane, 84. Hexahydrobenzotripyrane
Liebigs Annalen der Chemie, 1980AbstractDie Hexahydrobenzotripyrane 5 und 6 lassen sich durch katalytisches Hydrieren des Benzotripyranons 3 gewinnen, die weniger symmetrischen Isomere 21 und 12 aus der 1,2,4‐Benzoltriyltris(3‐oxypropionsäure) 16c durch Ringschlußreaktionen sowie katalytisches Hydrieren.
Claus Schmiz, Fritz Eiden
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Chemistry of Heterocyclic Compounds, 1985
Data on methods of synthesis, transformations, and spectroscopy of monocyclic six-membered, oxygen-containing heterocycles, viz., 2H-pyrans, are correlated and systematized for the first time in this review.
O. V. Drygina +2 more
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Data on methods of synthesis, transformations, and spectroscopy of monocyclic six-membered, oxygen-containing heterocycles, viz., 2H-pyrans, are correlated and systematized for the first time in this review.
O. V. Drygina +2 more
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Chemischer Informationsdienst, 1985
AbstractDihydropyranon (I) läßt sich nur in Einzelfällen,′ z.B. mit den Aminoketonen (XX), zu anellierten Heterocyclen wie (XXI) umsetzen.
F. EIDEN, K. T. WANNER
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AbstractDihydropyranon (I) läßt sich nur in Einzelfällen,′ z.B. mit den Aminoketonen (XX), zu anellierten Heterocyclen wie (XXI) umsetzen.
F. EIDEN, K. T. WANNER
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Strategies for the synthesis of bioactive pyran naphthoquinones
Organic & Biomolecular Chemistry, 2010Taking into account the numerous reports in the literature related to pyran naphthoquinones in searching for new pharmacologically promising molecules against different therapeutic targets, this review intends to explore the synthetic methodologies for preparing these bioactive compounds.
Vitor Francisco, Ferreira +2 more
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Pyrans, Thiopyrans, and Selenopyrans
1983Publisher Summary This chapter presents the literature for pyrans, thiopyrans, and selenopyrans. Pyran structure refers to a six-membered ring possessing one oxygen, sulfur, selenium, or telurium heteroatom singly bonded in a cyclic system of two double bonds and one tetrahedral atomic center.
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