- Halogen-dependent coupling reaction of alkynes with (Z)-3- halopropenoates catalyzed by nickel
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Ni-catalyzed coupling reaction of alkynes with (Z)-3-halopropenoates depended on the halogen of halopropenoates. The reaction with (Z)-3- bromopropenoate afforded cyclopentadienes and the reaction with (Z)-3- iodopropenoates gave pyrones.
- Kotora, Martin,Ishikawa, Masanori,Tsai, Fu-Yu,Takahashi, Tamotsu
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Read Online
- E-6-(1-PENTENYL)-2H-PYRAN-2-ONE FROM CARPENTER ANTS (CAMPONOTUS SPP.)
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A novel synthesis of the title compound, 3, is reported along with its identification as a component of the male mandibular gland secretion of some carpenter ants.
- Jones, Tappey H.,Fales, Henry M.
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Read Online
- A flexible route to bioactive 6-alkyl-α-pyrones
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Both 6-chloro-α-pyrones and 3-chlorobenzopyran-1-ones react with malonates followed by a double decarboalkoxylation to give the corresponding alkyl and alkenyl products.
- Qu, Yang,Kraus, George A.
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supporting information
p. 892 - 893
(2017/02/18)
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- 2H-pyran-2-ones from trichoderma viride and trichoderma asperellum
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Volatiles emitted by the soil fungi Trichoderma viride 272 and Trichoderma asperellum 328 were collected by using the closed loop stripping analysis (CLSA) headspace technique, and the obtained extracts were analysed by GC/MS. Several alkyl- and alkenyl-2H-pyran-2-ones, including known compounds 6-pentyl-2H-pyran-2-one and (E)-6-(pent-1-en-1-yl)-2H-pyran-2-one, and the new derivatives (E)-6-(pent-2-en-1-yl)-2H-pyran-2-one, 6-propyl-2H-pyran-2-one, and 6-heptyl-2H-pyran-2-one were found. The alkenyl derivative (E)-6-(hept-1-en-1- yl)-2H-pyran-2-one, previously tentatively identified from a marine Botrytis by MS analysis, was also detected. All alkenyl pyrones were synthesised by using a reported Stille coupling followed by lactonisation, whereas the alkylated pyrones were obtained through a reported synthetic approach by radical bromination of 5-alkylpent-2-en-5-olides and dehydrobromination. Because the yields in both cases were not satisfactory and fell a long way short of the yields reported for similar compounds, all compounds were synthesised again using a gold-catalysed coupling of terminal alkynes with propiolic acid recently developed by Schreiber and co-workers, giving high yields in all cases. A comparison of the synthetic methods is given. Copyright
- Wickel, Susanne M.,Citron, Christian A.,Dickschat, Jeroen S.
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p. 2906 - 2913
(2013/06/27)
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- Syntheses of α-pyrones using gold-catalyzed coupling reactions
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Sequential alkyne activation of terminal alkynes and propiolic acids by gold(I) catalysts yields compounds having α-pyrone skeletons. Novel cascade reactions involving propiolic acids are reported that give rise to α-pyrones with different substitution patterns.
- Luo, Tuoping,Dai, Mingji,Zheng, Shao-Liang,Schreiber, Stuart L.
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supporting information; experimental part
p. 2834 - 2836
(2011/07/07)
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- Gold(I)-catalyzed cycloisomerization of β-alkynylpropiolactones to substituted α-pyrones
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Substituted α-pyrones were straightforwardly synthesized in good to excellent yields by a new gold(I)-catalyzed rearrangement of β-alkynylpropiolactones.
- Dombray, Thomas,Blanc, Aurelien,Weibel, Jean-Marc,Pale, Patrick
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supporting information; experimental part
p. 5362 - 5365
(2011/02/27)
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- 6-Chloro-2(2H)-pyranone: A new 2(2H)-pyranone synthon
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6-Chloro-2(2H)-pyranone, which can be prepared in high yield from commercially available trans-glutaconic acid, undergoes facile Pd/Cu-catalyzed reaction with various 1-alkynes to give rise to the corresponding 6-(1-alkynyl)-2(2H)-pyranones in moderate to good yields. These last hitherto unknown compounds have been used as direct precursors to 6-alkyl- and 6-[(Z)-1-alkenyl]-2(2H)-pyranones.
- Biagetti, Matteo,Bellina, Fabio,Carpita, Adriano,Rossi, Renzo
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p. 607 - 610
(2007/10/03)
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- One-step synthesis of alpha-pyrones from acyl chlorides by the Stille reaction.
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Palladium-catalyzed stereoselective annulation of a functional vinylstannane by acyl chlorides gives the corresponding alpha-pyran-2-ones in good yields. This annulation most probably proceeds through a Stille reaction/cyclization sequence.
- Thibonnet, Jerome,Abarbri, Mohamed,Parrain, Jean-Luc,Duchene, Alain
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p. 3941 - 3944
(2007/10/03)
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- A novel route to 6-substituted and 5,6-disubstituted 2-pyrones
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6-Alkyl- and 6-(1-alkenyl)-5-iodo-2-pyrones, which are available as major products by reaction of the corresponding (Z)-2-en-4-ynoic acids with iodine and NaHCO3 in CH3CN, undergo insertion of activated zinc metal into their carbon-iodine bond to provide the corresponding 5-(iodozinc)-2-pyrones. Hydrolysis of these organometallics gives 6-substituted 2-pyrones in satisfactory yields including two natural products. On the other hand, the Pd-catalyzed reaction of the organozincs either with an activated alkenyl halide or with activated and deactivated (hetero)aryl halides provides 5,6-disubstituted 2-pyrones in fair to good yields.
- Bellina, Fabio,Biagetti, Matteo,Carpita, Adriano,Rossi, Renzo
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p. 2859 - 2863
(2007/10/03)
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- Synthesis of α-Pyrones from Vinylogous Thiol Esters and α-Oxo Ketene Dithioacetals
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Vinylogous thiol esters and α-oxo ketene dithioacetals can be converted into α-pyrones by a strategy involving 1,2-nucleophilic addition of ester, ketone, or hydrazone enolate anions, followed by acid-promoted rearrangement to a δ-keto ester, thiol ester, or acid and subsequent enol lactonization.These multistep procedures can be carried out without isolation and purification of intermediates and afford α-pyrones in good overall yields.The synthetic routes are complementary in terms of substitution patterns and limitations.
- Dieter, R. Karl,Fishpaugh, Jeffrey R.
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p. 2031 - 2046
(2007/10/02)
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