1629-58-9Relevant articles and documents
Floyd
, p. 2877 (1974)
A Convenient Preparation of Ethyl Vinyl Ketone
Byrne, Brian,Wengenroth, Karl J.
, p. 870 - 871 (1986)
A four-step synthesis of ethyl vinyl ketone conveniently gives 67percent overall yield.
Methylvinyl Ketone Formation over Synthetic Chrysotile
Suzuki, Eiichi,Idemura, Satoshi,Ono, Yoshio
, p. 1843 - 1846 (1987)
Selective formation of methylvinyl ketone (MVK) was attained over chrysotile, Mg3(OH)4Si2O5, through aldol condensation reaction between acetone and formaldehyde, the selectivity being 98 percent on both acetone and formaldehyde bases.Synthetic Co2+-substituted chrysotile, CoxMg3-x(OH)4Si2O5 (x= 0.15 or 0.9), catalyzed the reaction between acetone and methanol to give MVK and methylethyl ketone (MEK) with 75 percent selectivity on acetone basis.
Cu2O-CuO/Chitosan Composites as Heterogeneous Catalysts for Benzylic C?H Oxidation at Room Temperature
Kanarat, Jurin,Bunchuay, Thanthapatra,Klysubun, Wantana,Tantirungrotechai, Jonggol
, p. 4833 - 4840 (2021/10/07)
Recently, in catalysis, chitosan has been exploited as a macrochelating ligand for metal active species due to the presence of various functional groups in its structure. Moreover, copper-based catalysts are classified as one of the most environmentally friendly catalytic systems and their use for the oxidation of alkylarene has not been established much. Therefore, in this work, the hydrothermal synthesis of copper oxide-chitosan composites as heterogeneous catalysts for the benzylic C?H oxidation of alkylarene was investigated. Characterization results reveal mixed phases of CuO and Cu2O, inferring the ability of chitosan to act as a reducing sugar under the hydrothermal condition. The pre-existing interaction between copper species and chitosan as well as the co-existence of the Cu2O and CuO structures give rise to the efficient performance of the catalysts. The synthesized composites exhibit high activity for the oxidation of fluorene to 9-fluorenone at room temperature and small catalyst loading (1 mol % of Cu, >90 % conversion and 100 % selectivity). Superior TOF was observed, and a good scope of substrates can be converted to corresponding ketones in 48–97 % yields with these copper oxide-chitosan catalysts. In addition, the catalysts can be used for up to nine cycles without significant decrease of the activity.
K2S2O8-promoted C-Se bond formation to construct α-phenylseleno carbonyl compounds and α,β-unsaturated carbonyl compounds
Yang, Xue-Yan,Wang, Ruizhe,Wang, Lu,Li, Jianjun,Mao, Shuai,Zhang, San-Qi,Chen, Nanzheng
, p. 28902 - 28905 (2020/08/25)
A novel K2S2O8-promoted C-Se bond formation from cross-coupling under neutral conditions has been developed. A variety of aldehydes and ketones react well using K2S2O8 as the oxidant in the absence of catalyst and afford desired products in moderate to excellent yields. This protocol provides a very simple route for the synthesis of α-phenylseleno carbonyl compounds and α,β-unsaturated carbonyl compounds.
Changes in the Key Odorants and Aroma Profiles of Hamlin and Valencia Orange Juices Not from Concentrate (NFC) during Chilled Storage
Sellami, Ines,Mall, Veronika,Schieberle, Peter
, p. 7428 - 7440 (2018/06/19)
Application of the aroma extract dilution analysis (AEDA) on the volatiles isolated by extraction/SAFE distillation from NFC (not from concentrate) juice from Hamlin oranges revealed 51 odor-active constituents in the flavor dilution (FD) factor range of 8 to 8192 among which vanillin, wine lactone, and (R)-linalool appeared with the highest FD factors. The AEDA applied on the volatile fraction of the same batch of juice stored at 0 °C for 10 months under aseptic conditions showed clear changes in the aroma profile as well as in the FD factors of key odorants. The reduction in the intensity of the citrus-like, pungent, green odor attributes in the aroma profile correlated with the loss of 1-penten-3-one, acetaldehyde, and (Z)-3-hexenal and a clear decrease in hexanal, octanal, nonanal, decanal, and (E,E)-2,4-decadienal. Quantitation done by stabile isotope dilution assays followed by a calculation of odor activity values (ratio of concentration to odor thresholds in citrate buffer) confirmed that the quick loss of 1-penten-3-one and acetaldehyde already within a few weeks and a significant reduction in nearly all aldehydes over the storage time of 10 months were responsible for the changes in the overall aroma profile of the juice. The same approach applied on Hamlin juice from the next harvest year as well as on chilled stored NFC juice from Valencia oranges confirmed the results for another harvest year and another orange variety.
