pyrone การใช้

• It is isomeric with 4-pyrone.
• The most common natural products containing a 2-pyrone are the bufanolides and kavalactones.
• It is isomeric with 2-pyrone.
• This approach is less widely employed due to its limited utility and requirement for pyrone skeletons.
• Oxovitisin A, a pyranoanthocyanin found in wine, also contains a 2-pyrone element.
• Pyrone monoadducts do not absorb in the UVA range and hence cannot form cross-links with further UVA irradiation.
• An initial tautomerization occurs, followed by elimination of the leaving group to aromatize the pyrone ring and to generate the carbonyl ylide.
• Triacetic acid lactone is classified as a 2-pyrone compound owing to the ketone group on the C2 carbon in its dominant form.
• Once purified, khellin exists as colorless, odorless, bitter-tasting needle-shaped crystals and is classified as a gamma-pyrone, a furanochromone derivative.
• "' Verrucosidin "'is a toxic pyrone-type polyketide produced by " Penicillium aurantiogriseum ", Penicillium melanoconidium, and Penicillium polonicum.
• Next, the enolate complex adds to the pyrone through a Diels-Alder concerted reaction to form a bicyclic intermediate ( "'8 "').
• 2-Pyrone is used in organic synthesis as a building block for more complex chemical structures because it may participate in a variety of cycloaddition reactions to form bicyclic lactones.
• Then, the coordinated enolate can either add to the 2-pyrone ( "'3 "') through a Michael-aldol or Diels-Alder pathway.
• The furan monoadduct can absorb a second UVA photon leading to a second four-center photocycloaddition at the pyrone end of the molecule and hence the formation of a diadduct or cross-link.
• Tipranavir is a nonpeptidic HIV-1 protease inhibitor This sulfonamide containing 5, 6-dihydro-4-hydroxy-2-pyrone had emerged from screenings of 3-substituted coumarins and dihydropyrones.
• The photochemically reactive sites in psoralens are located at each of the carbon-carbon double bonds in the furan ring ( the five-member ring ) and the pyrone ring ( the six-member ring ).
• In the Michael-aldol pathway ( "'Scheme 2 "'), The coordinated oxaloacetate enolate performs a Michael addition to the ring of the pyrone to form intermediate "'4 " '.
• Chemically, quercetin is a member of a fairly extensive class of natural coloring matters derived from phenyl benzoyl-pyrone or flavone, the constitution of which followed on the researches of St von Kostanecki, A . G . Perkin, Herzig, Goldschmidt and others.
• The unusual multistep conversion of 5-acetyl-4-methoxy-6-methyl-2-pyrone ( "'3 "') to macrophomic acid is thought to proceed by either a concerted Diels-Alder reaction or a recently proposed 2-step Michael-aldol sequence.
• The intermolecular reaction of the hydroxy-pyrone and ?, ? unsaturated ester shown below suffered from poor yield and regioselectivity; however, when directed by phenylboronic acid the desired adduct could be obtained in 61 % yield after cleavage of the boronate with 2, 2-dimethyl-1, 3-propanediol.