25564-22-1Relevant articles and documents
Concurrent Strong Acid and Base Catalysis. Synthesis of Cyclopentenones
Stowell, John C.,Hauck, Henry F.
, p. 2428 - 2429 (1981)
2-Alkyl-2-cyclopenten-1-ones were prepared in one operation from γ-keto aldehyde acetals by acid-catalyzed hydrolysis of the acetal and base-catalyzed aldol cyclization using mixed ion-exchange resins.
-
Roumestant,M.L. et al.
, p. 755 - 757 (1976)
-
-
Tsuji,J. et al.
, p. 39 - 40 (1979)
-
-
Oshima,K. et al.
, p. 4446 - 4447 (1973)
-
Catalytic intermolecular Pauson - Khand reactions in supercritical ethylene
Jeong, Nakcheol,Hwang, Sung Hee
, p. 636 - 638 (2000)
Ethylene is not only a substrate, but also a solvent: Catalytic intermolecular Pauson - Khand reactions of terminal alkynes were carried out in supercritical ethylene to provide 2-substituted cyclopentenones in moderate to high yields. Under these conditions, even a low pressure of CO (5 atm) is sufficient for the reaction to take place.
Characterization of initial reaction intermediates in heated model systems of glucose, glutathione, and aliphatic aldehydes
Wang, Tianze,Zhen, Dawei,Tan, Jia,Xie, Jianchun,Cheng, Jie,Zhao, Jian
, (2019/09/12)
To understand the effect of lipid degradation on Maillard formation of meaty flavors, initial reaction intermediates in model systems of glucose–glutathione with hexanal, (E)-2-heptenal, or (E,E)-2,4-decadienal were identified by HPLC–MS and by NMR. Besides Amadori compounds, hemiacetals and thiazolidines via addition of sulfhydryl to carbonyl or to the conjugated olefinic bond were found. Concentrations of all intermediates increased with reaction time while degradation of the intermediates with a glutathione moiety helped formation of thiazolidines with cysteinylglycine. The unsaturated aldehydes (E)-2-heptenal and (E,E)-2,4-decadienal exhibited high reactivity against glucose for glutathione, yielding higher levels of intermediate compounds than from glucose. Heating prepared intermediates reversibly released the original aldehydes, which caused various compounds formed by retro-aldol, oxidation, etc. to react with H2S and NH3. Among them, formation pathways including 3-nonen-2-one, 2-hexanoylfuran, and six dialkylthiophenes (e.g., 2-ethyl-5-(1-methylbutyl)thiophene) were proposed for the first time.
Aldol Condensation of Cyclopentanone with Valeraldehyde Over Metal Oxides
M?ki-Arvela, P?ivi,Shcherban, Nataliya,Lozachmeur, Chloé,Er?nen, Kari,Aho, Atte,Smeds, Annika,Kumar, Narendra,Peltonen, Janne,Peurla, Markus,Russo, Vincenzo,Volcho, Konstantin P.,Murzin, Dmitry Yu.
, p. 1383 - 1395 (2019/02/26)
Kinetics of the cross aldol condensation of valeraldehyde with cyclopentanone was investigated in a batch reactor under atmospheric pressure at 130?°C using heterogeneous metal modified oxides, such as CeO2–MgO, FeO–MgO, FeO–CaO as well as pristine CaO as catalysts. The catalysts were prepared either by evaporation impregnation or deposition precipitation methods and characterized by XRD, TEM, SEM, nitrogen adsorption, ammonia and CO2 TPD. The results revealed that an optimum amount of strong basic sites gives the highest ratio between cross condensation and self-condensation products of valeraldehyde. The highest yield of the desired product 2-pentylidenecyclopentanone (66%) was obtained with FeO–MgO prepared by the deposition precipitation methods. Graphical Abstract: Cross-condensation of valeraldehyde with cyclopentanone was investigated over heterogeneous Fe–CaO, CeO–MgO, FeO–CaO and CaO catalysts at 130?°C using cyclopentanone as a solvent and reactant. The highest yield of the desired product, 2-pentylidene-cyclopentanone, finding applications as fragrances, flavours and pharmaceuticals, was 66% obtained over FeO–MgO catalyst exhibiting both acid and basic sites.[Figure not available: see fulltext.].
Preparation method of methyl dihydrojasmonate
-
Paragraph 0026; 0027; 0056; 0057; 0060; 0062, (2018/05/01)
The invention discloses an efficient synthesis method of methyl dihydrojasmonate. Under catalysis of homogeneous rhodium and organic nitric oxide, 1-heptyne and ethylene have Pauson-Khand reaction, 2-amyl-2-cyclopentenone is rapidly and efficiently obtained, and an intermediate is subjected to addition and decarboxylation by dimethyl malonate to obtain the methyl dihydrojasmonate. The efficient synthesis method mainly has the advantages that 1-heptyne and ethylene Pauson-Khand reaction yield is effectively improved by the aid of the organic nitric oxide, and usage of rhodium catalysts is reduced. Compared with a traditional methyl dihydrojasmonate production method, the method has the advantages that route steps are short, atom economy is high, the cost is low, and the method is suitable for scale production of the methyl dihydrojasmonate.