Results 131 to 140 of about 5,078 (168)
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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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ChemInform Abstract: KONDENSIERTE PYRANE
Chemischer Informationsdienst. Organische Chemie, 1970AbstractVersuche, aus dem Cumarin (I) mit Formaldehyd (II) und Phenylacetylen (III) durch eine Dreikohlenstoffkondensation das Propinylcumarin (IV) darzustellen, lieferten neben 82% Dicumarol (VI) das Pyranobenzopyran (V) in 14%iger Ausbeute.
KARL ERNST SCHULTE +2 more
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Photochemical rearrangement of 4H-pyran-4-ones to 2H-pyran-2-ones
Journal of the Chemical Society D: Chemical Communications, 1971Irradiation of 2,6-disubstituted-3,5-diphenyl-4H-pyran-4-ones (Ia,b) with a medium-pressure mercury lamp yielded 3,6-diphenyl-4,5-disubstituted-2H-pyran-2-ones (IVa,b).
N. Ishibe, M. Odani, M. Sunami
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Synthesis of Novel Hybrid 4H-Pyran-lipoic and 4H-Pyran-azetidine Derivatives
Synthesis, 2017In this study, a molecular hybridization strategy was used to design and synthesize two novel series of hybrid compounds: 4H-pyran-lipoic and 4H-pyran-azetidine, employing ammonium hydroxide and involving the participation of aldehydes, malononitrile, and compounds derived from β-ketoesters to obtain the products with good yields.
Miguel Vázquez +7 more
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Stereocontrolled Synthesis of Highly Functionalized Spirocyclic Pyrans.
ChemInform, 2006AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Stephen J, Hobson, Rodolfo, Marquez
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The Journal of Organic Chemistry, 1996
5-(Trimethylstannyl)-2H-pyran-2-one (11) and 3-(trimethylstannyl)-2H-pyran-2-one (30), readily prepared from the corresponding bromo-2H-pyran-2-ones, undergo Pd(0)-catalyzed coupling reactions with a variety of enol triflates to give 5- and 3- substituted 2H-pyran-2-ones, respectively. This reaction is applicable to the enol triflates of 14beta-hydroxy-
Zhi, Liu, Jerrold, Meinwald
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5-(Trimethylstannyl)-2H-pyran-2-one (11) and 3-(trimethylstannyl)-2H-pyran-2-one (30), readily prepared from the corresponding bromo-2H-pyran-2-ones, undergo Pd(0)-catalyzed coupling reactions with a variety of enol triflates to give 5- and 3- substituted 2H-pyran-2-ones, respectively. This reaction is applicable to the enol triflates of 14beta-hydroxy-
Zhi, Liu, Jerrold, Meinwald
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Archiv der Pharmazie, 1978
AbstractPyranopyrimidincarbonsäureester lassen sich aus Barbitursäuren, Paraformaldehyd und ungesättigten Carbonsäureestern darstellen. Drei daraus durch Verseifung erhaltene Pyranopyrimidincarbonsäuren wurden auf antiphlogistische Wirksamkeit geprüft.
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AbstractPyranopyrimidincarbonsäureester lassen sich aus Barbitursäuren, Paraformaldehyd und ungesättigten Carbonsäureestern darstellen. Drei daraus durch Verseifung erhaltene Pyranopyrimidincarbonsäuren wurden auf antiphlogistische Wirksamkeit geprüft.
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ChemInform, 1997
AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Z. LIU, J. MEINWALD
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AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Z. LIU, J. MEINWALD
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MO study of 2,2,4-trimethyl-2H-pyran, the simplest stable 2H-pyran derivative
Collection of Czechoslovak Chemical Communications, 1987On the basis of MNDO optimized molecular geometries of the title compound I and its acyclic valence tautomers II and III it is demonstrated that the ability to isolate heterocyclic form I can be interpreted by its relatively lowest SCF-molecular energy calculated in MNDO or 4-31G, resp., orbital bases.
Stanislav Böhm, Josef Kuthan
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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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