- Synthesis of the racemate and both enantiomers of massoilactone
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A simple and efficient synthesis of (±)-massoilactone (1) as a key substance for the butter and milk flavor was accomplished from n-hexanal in only a few steps. Application of its racemic synthesis enabled natural (R)-(-)-and unnatural (S)-(+)-massoilacto
- Ishikawa, Masashi,Amaike, Masayasu,Itoh, Masamichi,Warita, Yasuhiro,Kitahara, Takeshi
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- A VERY SIMPLE SYTHESIS OF NATURAL SATURATED δ-SUBSTITUTED δ-LACTONES. THE PHEROMONE OF Vespa orientalis
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Very facile syntheses of racemic massoia lacton and the pheromone of Veapa orientialis have been achieved starting from dehydroacetic acid.
- Bacardit, Ramon,Moreno-Manas, Marcial
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- Allyl-Nickel Catalysis Enables Carbonyl Dehydrogenation and Oxidative Cycloalkenylation of Ketones
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We herein disclose the first report of a first-row transition metal-catalyzed α,β-dehydrogenation of carbonyl compounds using allyl-nickel catalysis. This development overcomes several limitations of previously reported allyl-palladium-catalyzed oxidation, and is further leveraged for the development of an oxidative cycloalkenylation reaction that provides access to bicycloalkenones with fused, bridged, and spirocyclic ring systems using unactivated ketone and alkene precursors.
- Huang, David,Szewczyk, Suzanne M.,Zhang, Pengpeng,Newhouse, Timothy R.
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supporting information
p. 5669 - 5674
(2019/04/26)
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- PPARS AGONIST ACTIVITY ENHANCING DRUG
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According to the present invention, PPARs agonist activity is enhanced in order to improve metabolic syndrome, hyperlipidemia, and diabetes. Provided is a compound having a lactone structure comprising formula (9).
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Paragraph 0018-0019; 0021-0022
(2015/03/03)
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- High-Performance Isocyanide Scavengers for Use in Low-Waste Purification of Olefin Metathesis Products
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Three isocyanides containing a tertiary nitrogen atom were investigated for use as small-molecule ruthenium scavenging agents in the workup of olefin metathesis reactions. The proposed compounds are odorless, easy to obtain, and highly effective in removi
- Szczepaniak, Grzegorz,Urbaniak, Katarzyna,Wierzbicka, Celina,Kosiński, Krzysztof,Skowerski, Krzysztof,Grela, Karol
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p. 4139 - 4148
(2015/12/30)
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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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- αβ-Unsaturated δ-valerolactones through RCM-isomerization sequence
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αβ-Unsaturated δ-lactones are accessible via a sequential ring-closing metathesis (RCM) double-bond migration reaction starting from butenoates of allyl alcohols. This approach proceeds efficiently with lower catalyst loadings and higher initial substrate concentrations compared to the alternative RCM of acrylates derived from homoallylic alcohols. Georg Thieme Verlag Stuttgart . New York.
- Schmidt, Bernd,Kunz, Oliver
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supporting information; experimental part
p. 851 - 854
(2012/06/15)
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- Thieme chemistry journal awardees - Where are they now? aldol synthesis by anti-markovnikov hydration of propargyloxy substrates: Feasibility, stereospecifity, and reiterative alkynylation-hydration
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Aldol derivatives have been synthesized by redox-neutral catalytic anti-Markovnikov hydration of propargyloxy sub-strates. A reiterative sequence of aldehyde alkynylation and alkyne hydration leads to 1,3-polyol derivatives. Georg Thieme Verlag Stuttgart.
- Hintermann, Lukas,Kribber, Thomas,Labonne, Aurélie,Paciok, Eva
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scheme or table
p. 2412 - 2416
(2009/12/08)
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- The β-lactone route to β-hydroxy or α,β-unsaturated γ- and δ-lactones. Syntheses of (±)-Massoialactone and (±)-Prelactone B
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Aqueous HF promotes the translactonization of silyloxy β-lactones into β-hydroxy or α,β-unsaturated γ- and δ-lactones. The reaction is studied from a theoretical point of view and applied to the racemic synthesis of two natural bioactive δ-lactones.
- Fournier, Lycia,Gaudel-Siri, Anouk,Kocieński, Philip J.,Pons, Jean-Marc
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p. 107 - 111
(2007/10/03)
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- The first In(OTf)3-catalyzed conversion of kinetically formed homoallylic alcohols into the thermodynamically preferred regioisomers: Application to the synthesis of 22α-sterols
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A retro-ene reaction that generates the parent aldehyde and a sigmatropic rearrangement are involved in the In(OTf)3-catalyzed conversion of homoallylic alcohols 1 into the thermodynamically favored regioisomers 2. This method can be used for the stereocontrolled synthesis of linear homoallylic 22α-sterols from their readily accessible branched 22β isomers.
- Loh, Teck-Peng,Tan, Kui-Thong,Hu, Qi-Ying
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p. 2921 - 2922
(2007/10/03)
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- A CONVENIENT SYNTHESIS OF HOMOCHIRAL δ-ALKYLATED α,β-UNSATURATED δ-LACTONES
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The tert-butyl propiolate ion serves as a convenient and efficient nucleophile in boron trifluoride-catalyzed openings of homochiral, mono-substituted epoxides.The resulting tert-butyl 5-hydroxy-2-alkynoates are converted into the title compounds upon semihydrogenation followed by acid hydrolysis.Specific examples include the synthesis of parasorbic acid and massoilactone, two naturally derived lactones of the present type.The scope of the synthetic protocol is discussed.
- Hoeyer, Thomas,Kjaer, Anders,Lykkesfeldt, Jens
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p. 1042 - 1051
(2007/10/02)
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- Stereoselective Synthesis of Alcohols, XXII. E/Z-Selectivity on Addition of α-Substituted Allylboronates to Aldehydes
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α-Heterosubstituted allylboronates 7 are prepared.Addition of 7 to aldehydes results in E/Z-isomeric homoallyl alcohols 13 and 14.The reasons for the predominant formation of the Z-isomer 14 are discussed.The Z-bromo olefins 16 and 20 obtained in this way serve as starting point for chain extension or formation of δ-lactones 21.
- Hoffmann, Reinhard W.,Landmann, Bernd
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p. 1039 - 1053
(2007/10/02)
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- A NEW SYNTHESIS OF α,β-UNSATURATED γ- AND δ-LACTONS VIA INTRAMOLECULAR ACYLATION OF α-SULFINYL CARBANION
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A new synthesis of α,β-unsaturated γ- and δ-lactones involving the intramolecular acylation of α-sulfinyl carbanion followed by pyrolisis is described.
- Pohmakotr, Manat,Jarupan, Prapanpong
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p. 2253 - 2256
(2007/10/02)
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- Z-SELECTIVE FORMATION OF SUBSTITUTED HOMOALLYL ALCOHOLS
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The α-substituted allylboronates 4 add to aldehydes giving with high Z-preference the homoallyl alcohols 1.The Z-vinyl bromides obtained were further converted into δ-lactones.
- Hoffmann, Reinhard W.,Landmann, Bernd
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p. 3209 - 3212
(2007/10/02)
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- A NEW METHOD FOR SYNTHESIS OF α,β-UNSATURATED δ-LACTONES VIA MICHAEL ADDITION USING METHYL (PHENYLSULFINYL)ACETATE
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Various α,β-unsaturated δ-lactones were synthesized via Michael addition of methyl (phenylsulfinyl)acetate to alkyl vinyl ketones in the presence of tributylphosphine.For example, racemic massoia lactone was obtained in 49percent overall yield.
- Yoshida, Takashi,Saito, Shojiro
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p. 1587 - 1590
(2007/10/02)
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- Thermal Rearrangement Reactions of Tricarbonyliron Lactone Complexes
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A variety of tricarbonyliron lactone complexes (1)-(12) undergo thermal decomposition upon warming in deoxygenated solvents to give products arising from decarbonylation, decarboxylation and rearrangement pathways.The products of the reactions were characterised by spectroscopic or X-ray crystallographic methods, or in some cases, by independent synthesis.Mechanisms to account for the various transformations are also proposed.
- Annis, Gary D.,Ley, Steven V.,Self, Christopher R.,Sivaramakrishnan, Ramamoorthy,Williams, David J.
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p. 1355 - 1362
(2007/10/02)
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- General Approach to the Synthesis of Naturally Occurring δ-Lactones
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The adducts from thermal and/or high-pressure Diels-Alder reactions between 1-methoxybuta-1,3-diene and carbonyl compounds (glyoxylates, aldehydes) are utilized as the starting materials for the syntheses of naturally occurring δ-lactones.Total syntheses of massoilactone, 6-phenyl-2-pyrone, and 2-methoxy-6-undecyl-5,6-dihydro-2H-pyran are described.A general approach to these syntheses is presented.
- Chmielewski, Marek,Jurczak, Janusz
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p. 2230 - 2233
(2007/10/02)
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