Results 181 to 190 of about 3,742 (239)

ChemInform Abstract: PHOTOCHEMICAL REARRANGEMENT OF 4H‐PYRANS AND OF DIENONES TO 2H‐PYRANS

Chemischer Informationsdienst, 1980
AbstractDie Photoreaktivität der 4H‐Pyrane (I) wurde mit Hilfe von Fluoreszenz‐ und Phosphoreszenz‐Messungen, Desaktivierungsmessungen für den Singulettzustand und durch Bestimmung von Quantenausb.
F. FOURNIER, J. BERTHELOT, NGUYEN KIM CUONG NGUYEN KIM CUONG, J.‐J. BASSELIER   +3 more
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4H-pyrans (review)

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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Pyrane, 84. Hexahydrobenzotripyrane

Liebigs Annalen der Chemie, 1980
AbstractDie 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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ChemInform Abstract: PYRANS, 100. 5,6‐DIHYDRO‐2H‐PYRAN‐3(4H)‐ONE AS A SYNTHON FOR PYRAN‐ANNULATED HETEROCYCLIC COMPOUNDS

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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Strategies for the synthesis of bioactive pyran naphthoquinones

Organic & Biomolecular Chemistry, 2010
Taking 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, Sabrina Baptista, Ferreira, Fernando de Carvalho, da Silva   +2 more
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Pyrans, Thiopyrans, and Selenopyrans

1983
Publisher 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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Immunopharmacology of pyran copolymer

Pharmacological Research Communications, 1978
P, Puccetti, A, Giampietri
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Investigation of positron scattering from 2H-pyran, 4H-pyran, and pyrrole molecules

Journal of Physics B: Atomic, Molecular and Optical Physics
Abstract The scattering cross-sections for positron-biomolecule interaction are an essential input for the Monte-Carlo simulation techniques. In the present work, we have reported the elastic integral, differential, momentum transfer, and total ionization cross-sections for scattering of positron from 2H-pyran, 4H-pyran, and pyrrole ...
Snigdha Sharma, Dhanoj Gupta
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Review on Synthesis and Medicinal Application of Dihydropyrano[3,2-b]Pyrans and Spiro-Pyrano[3,2-b]Pyrans by Employing the Reactivity of 5-Hydroxy-2-(Hydroxymethyl)-4H-Pyran-4-One

Polycyclic Aromatic Compounds, 2022
Biplob Borah, Raju L Chowhan, Kartikey Dhar Dwivedi   +2 more
exaly  

Pyrans and Fused Pyrans: (i) Structure

1984
P.J. Brogden, C.D. Gabbutt, J.D. Hepworth   +2 more
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