106-26-3Relevant academic research and scientific papers
Comparison of the Key Aroma Compounds in Fresh, Raw Ginger (Zingiber officinale Roscoe) from China and Roasted Ginger by Application of Aroma Extract Dilution Analysis
Schaller, Tanja,Schieberle, Peter
, p. 15292 - 15300 (2020)
By application of a comparative aroma extract dilution analysis on the volatile fractions isolated by solvent extraction and solvent-assisted flavor evaporation (SAFE) from fresh raw Chinese ginger (Zingiber officinale Roscoe) and roasted ginger, 21 or 33 odorants, respectively, with flavor dilution (FD) factors in the range of 32-4096 were identified. In raw ginger, the highest FD factors were found for (E)-isoeugenol, 1,8-cineol, vanillin, geranial, and linalool. After roasting, in particular, the FD factors of 3-(methylthio)propanal (cooked potato-like), 4-hydroxy-2,5-dimethyl-3(2H)-furanone (caramel-like), 3-hydroxy-4,5-dimethyl-2(5H)-furanone (seasoning-like), and geraniol were substantially increased. The application of static headspace/olfactometry (SHO) on ground raw ginger revealed a high FD factor for highly volatile acetaldehyde which clearly decreased after roasting. By contrast, the SHO application revealed high FD factors for malty smelling methylpropanal and 3-methylbutanal, which both were exclusively detected in roasted ginger. Thirteen odorants, namely, decanoic acid, (Z)-2-decenal, (Z)-4-decenal, (E)-4,5-epoxy-(E)-2-decenal, (E)-4,5-epoxy-(E)-2-undecenal, fenchol, (Z)-3-hexenal, 3-hydroxy-4,5-dimethyl-2(5H)-furanone, 4-hydroxy-2,5-dimethyl-3(2H)-furanone, 3-methyl-2-buten-1-thiol, 2-methylpropanal, (E)-2-nonenal, and 1-nonen-3-one, were identified in ginger for the first time. Chiral analysis showed a much higher percent by weight portion for the (R)-enantiomer in citronellal, citronellol, and linalool, which was not much changed during pan-frying.
A Convenient Preparation of Ketones by the Oxidation of Secondary Alcohols with Chromium(VI) Trioxide in Aprotic Solvent in the Presence of "Wet"-Aluminium Oxide
Hirano, Masao,Nagasawa, Sonoko,Morimoto, Takashi
, p. 2857 - 2859 (1991)
The oxidation of aliphatic and alicyclic secondary alcohols with chromium(VI) trioxide in the presence of "wet"-aluminium oxide in hexane gave the corresponding ketones in excellent yields under mild conditions.
Synthesis of (sulfonyl)methylphosphonate analogs of prenyl diphosphates
Lodewyk, Michael W.,Lui, Victor G.,Tantillo, Dean J.
, p. 170 - 173 (2010)
Syntheses of several (sulfonyl)methylphosphonate analogs of geranyl, neryl, and farnesyl diphosphates are described. Key steps include utilization of an (E)-selective Horner-Wadsworth-Emmons olefination which couples an aldehyde to the sulfone phosphonate moiety, and a selective reduction of the resulting dienyl sulfone phosphonate substrates.
TRANSITION-METAL CATALYZED OXIDATION OF ALCOHOLS TO ALDEHYDES AND KETONES BY MEANS OF Me3SiOOSiMe3
Kanemoto, Shigekazu,Oshima, Koichiro,Matsubara, Seijiro,Takai, Kazuhiko,Nozaki, Hitosi
, p. 2185 - 2188 (1983)
Pyridinium dichromate-Me3SiOOSiMe3 system has been found to be effective for the oxidation of alcohols to the corresponding carbonyl compounds.Selective oxidation of primary alcohols in the presence of secondary ones with RuCl2(PPh3)3-Me3SiOOMe3 is also described.
Oxidations with hydrogen peroxide catalysed by the [WZnMn(II)2(ZnW9O34)2]12- polyoxometalate
Neumann,Juwiler
, p. 8781 - 8788 (1996)
Polyoxometalates can be used as catalysts for the activation of molecular oxygen and 30% aqueous hydrogen peroxide for the selective transformation of various organic substrates. In this paper results are presented for the oxidation of alkenes, dienes, alkenols, and sulfides using 30% aqueous H2O2 as oxidant and [WZnMn(II)2(ZnW9O34)2]12- as catalyst. In certain but not all cases high reactivity, chemoselectivity and stereospecificity has been observed especially in the epoxidation of alkenols with primary hydroxyl units.
Catalysis of giant palladium cluster complexes, highly selective oxidations of primary allylic alcohols to (α,β-unsaturated aldehydes in the presence of molecular oxygen
Kaneda, Kiyotomi,Fujie, Yoko,Ebitani, Kohki
, p. 9023 - 9026 (1997)
A giant Pd cluster, Pd561phen60(OAc)180 has high catalytic activity for the selective oxidations of various primary allylic alcohols to the corresponding α,β-unsaturated aldehydes in the presence of molecular oxygen under mild reaction conditions. A Pd cluster anchored on TiO2, also catalyzes the above oxidations; the heterogeneous Pd561 cluster catalyst is easily separated from the reaction mixture and is reusable.
Synthesis of Allyl Acetals and Their Catalytic Claisen-Cope Rearrangement
Nakabayashi, Kazuhiro,Ooho, Masato,Niino, Teppei,Kitamura, Tsugio,Yamaji, Teizo
, p. 157 - 164 (2004)
We have synthesized various types of acetals using 3-methyl-3-butenal and 2-alkenyl, furfuryl, benzyl, p-substituted benzyl, and 2-pentynyl alcohols. These acetals have given corresponding aldehydes after an acid catalytic reaction. Trifluoroacetic acid (CF3COOH) was the best catalyst. The best yield attained was 79% when 3-methyl-3-butenal di(trans-2-pentenyl) acetal was used as a substrate. We also demonstrated that this reaction proceeded via a Claisen-Cope rearrangement.
Divergent synthesis of four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid, esters and evaluation for the antifungal activity
Wang, Weiwei,Zhang, Xiaoteng,Zhao, Yu,Liu, Xinlei,Zhang, Zhenhua,Wang, Mingan
, (2018)
The four isomers of 6,7-dihydroxy-3,7-dimethyloct-2-enoic acid 2 were synthesized via the selective direct Sharpless asymmetry dihydroxylation of geraniol as the key step in 35.0%-48.0% overall yields with 91.9%-97.7% ee values for esters 4 and 31.3%-36.4% overall yields with 90.3-97.5% ee values for acids 2 using cis- and trans-geraniol as raw materials. Their structures were characterized by 1H, 13C NMR and HR-ESI-MS data. The in vivo bioassay results showed that the chiral acid (Z, S)-2 was a good lead compound with 80%-100% inhibitory rates against P. cubensis, E. graminis, P. sorghi and C. gloeosporioides at the concentration of 400μg/mL.
Highly efficient oxidation of alcohols and aromatic compounds catalysed by the Ru-Co-Al hydrotalcite in the presence of molecular oxygen
Matsushita, Tsuyoshi,Ebitani, Kohki,Kaneda, Kiyotomi
, p. 265 - 266 (1999)
The ruthenium hydrotalcite having cobalt cations, Ru-Co-Al-CO3 HT, is an effective heterogeneous catalyst for the oxidation of various kinds of alcohols in the presence of molecular oxygen.
Engineering the enantioselectivity of yeast old yellow enzyme Oye2Y in asymmetric reduction of (E/Z)-citral to (R)-citronellal
Ying, Xiangxian,Yu, Shihua,Huang, Meijuan,Wei, Ran,Meng, Shumin,Cheng, Feng,Yu, Meilan,Ying, Meirong,Zhao, Man,Wang, Zhao
, (2019)
The members of the Old Yellow Enzyme (OYE) family are capable of catalyzing the asymmetric reduction of (E/Z)-citral to (R)-citronellal—a key intermediate in the synthesis of L-menthol. The applications of OYE-mediated biotransformation are usually hampered by its insufficient enantioselectivity and low activity. Here, the (R)-enantioselectivity of Old Yellow Enzyme from Saccharomyces cerevisiae CICC1060 (OYE2y) was enhanced through protein engineering. The single mutations of OYE2y revealed that the sites R330 and P76 could act as the enantioselectivity switch of OYE2y. Site-saturation mutagenesis was conducted to generate all possible replacements for the sites R330 and P76, yielding 17 and five variants with improved (R)-enantioselectivity in the (E/Z)-citral reduction, respectively. Among them, the variants R330H and P76C partly reversed the neral derived enantioselectivity from 32.66% e.e. (S) to 71.92% e.e. (R) and 37.50% e.e. (R), respectively. The docking analysis of OYE2y and its variants revealed that the substitutions R330H and P76C enabled neral to bind with a flipped orientation in the active site and thus reverse the enantioselectivity. Remarkably, the double substitutions of R330H/P76M, P76G/R330H, or P76S/R330H further improved (R)-enantioselectivity to >99% e.e. in the reduction of (E)-citral or (E/Z)-citral. The results demonstrated that it was feasible to alter the enantioselectivity of OYEs through engineering key residue distant from active sites, e.g., R330 in OYE2y.
