Results 121 to 130 of about 2,744 (177)

NMR spectra of 2‐pyrone and 2‐pyrone derivatives

Journal of Heterocyclic Chemistry, 1969
AbstractAn analysis of the complex NMR spectrum of 2‐pyrone is presented and the spectra of a series of variously substituted 2‐pyrones and 5,6‐dihydro‐2‐pyrones are discussed. It is demonstrated that NMR spectroscopy affords a convenient and reliable method of assigning the position of substituents on the 2‐pyrone nucleus.
W. H. Pirkle, Martin Dines
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Pyrones as bacterial signaling molecules

Nature Chemical Biology, 2013
Bacteria communicate via small diffusible molecules and thereby mediate group-coordinated behavior, a process referred to as quorum sensing. The prototypical quorum sensing system found in Gram-negative bacteria consists of a LuxI-type autoinducer synthase that produces N-acyl homoserine lactones (AHLs) as signals and a LuxR-type receptor that detects ...
Alexander O Brachmann, Sophie Brameyer, Darko Kresovic, Ivana Hitkova, Yannick Kopp, Christian Manske, Karin Schubert, Helge B Bode, Ralf Heermann   +8 more
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Photocycloaddition Reactions of 2-Pyrones

ChemInform, 2003
AbstractFor Abstract see ChemInform Abstract in Full Text.
Tetsuro Shimo, Kenichi Somekawa
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Synthesis of pyrone carbaldehydes, pyrone sulfonium ylides and related epoxides

Journal of Heterocyclic Chemistry, 2009
Abstract magnified imageHexaminium salts of 4‐pyrones 3a, 3b were synthesized by treatment of 2‐(4‐bromomethylphenyl)‐6‐methyl‐4H‐pyran‐4‐one 2a and 2‐(4‐bromomethylphenyl)‐6‐phenyl‐4H‐pyran‐4‐one 2b with hexamethyl‐enetetramine in chloroform in 71 and 84% yields respectively.
Aziz Shahrisa, Mahnaz Saraei
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Pyrone studies. Linear α-pyrone route to protected β-polyketones

Canadian Journal of Chemistry, 1968
Preliminary studies on an alternative polypyrone route to protected β-polyketo acid chains are reported. The synthesis of the basic pyrone units involved and their conversion to C-3 acylated compounds are described.
J. L. Douglas, T. Money
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Alkylative carbonyl transposition of dihydro-α-pyrones to dihydro-α-pyrones

Tetrahedron Letters, 1993
Abstract Dihydro-α-pyrones ( 2 ) are prepared from β-hydroxy ketones ( 1 ). Dihydropyrones ( 2 ) are transformed to unsaturated δ-lactones ( 4 ) via an alkylative 1,3-carbonyl transposition.
A. Nangia, P.Bheema Rao
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On the nitration of 2‐pyrone

Journal of Heterocyclic Chemistry, 1969
AbstractA 1:1 adducl of 2‐pyrone and nitronium fluoroborate has been delected by nmr and is a possible precursor of 5‐nitro‐2‐pyrone, a subsequently formed product. From comparison of the nmr spectra of the 1:1 adduct and 2‐methoxypyrylium fluoroborate, the adduct is believed to be the pyrylium fluoroborate derived from nitration of the carbonyl oxygen
W. H. Pirkle, M. Dines
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Preparation of the Geranyl-α-pyrone (±)-Aurantiacone via a New Pyrone Synthesis

Synlett, 2007
The structure of the leaf resin geranyl-α-pyrone auranti-acone isolated from Mimulus ( = Diplacus) aurantiacus (Curtis) Jeps. (Scrophulariaceae) was confirmed through synthesis. The key step is lactonization of the sensitive 5-hydroxy-3-oxopent-4-enoic acid under mild conditions, which can be released from the corresponding bispotassium salt.
Uwe Beifuss, Dietmar Schmidt, Jürgen Conrad, Iris Klaiber, Sabine Mika   +4 more
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Exchange Reactions of γ-Pyrone and Synthesis of Deuterated Pyrones

Journal of the American Chemical Society, 1952
R. C. Lord, W. D. Phillips
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Exchange Reactions of 4-Pyrone and 4-Pyrone Derivatives

The Journal of Organic Chemistry, 1964
D. W. Mayo, P. J. Sapienza
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