6789-80-6Relevant academic research and scientific papers
The synthesis of 3,4-2H2-3Z-Hexenal and 6,6,62H3-3Z-Hexenal
Fielder,Rowan
, p. 465 - 470 (1995)
6,6,6-2H3-3Z-Hexenal (3b) has been prepared in 89% yield and in greater than 94% purity by the oxidation of 6,6,63H3-3Z-Hexen-1-of (2b) with the Dess/Martin periodinane (1) in fluorotrichloromethane (freon 11). Use of the freon solvent greatly improved the recovery of this volatile aldehyde. Similarly the oxidation of 3,4-2H2-3Z-hexen-1-of (5) yielded 3,4-2H2-3Z-hexenal (6) in a 92% isolated yield with a purity of greater than 99%. 3,4-2H2-3Z-Hexen-1-of (5) Was prepared in 87% by the catalytic deuterogenation of 3-hexyn-1-of (4) in an improved synthetic procedure,
Method for synthesizing geraniol from piperylene (by machine translation)
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Paragraph 0038-0041; 0044-0045, (2020/07/12)
The method comprises the following steps: reacting piperylene with carbon monoxide and hydrogen to prepare an intermediate cis -3 -hexene -1 - aldehyde; and preparing the geraniol through hydrogenation. The yield of the leaf alcohol is 81.56-92 .73percent, the yield of the cis -3 - hexenyl -1 - aldehyde is 80.69-88 .13percent, the yield of the leaf alcohol is -3 - 54.94-80 .35percent (calculated by pentadiene), the yield of the leaf alcohol is 99.2-99 .50percent.1 - percent, and the yield fluctuation range of the leaf alcohol is 10 within 55.53-80 .97percent percent of the yield of the leaf 0.4 alcohol in 98.36-99 .60percent percent. (by machine translation)
Harnessing Secondary Coordination Sphere Interactions That Enable the Selective Amidation of Benzylic C-H Bonds
Jung, Hoimin,Schrader, Malte,Kim, Dongwook,Baik, Mu-Hyun,Park, Yoonsu,Chang, Sukbok
supporting information, p. 15356 - 15366 (2019/10/22)
Engineering site-selectivity is highly desirable especially in C-H functionalization reactions. We report a new catalyst platform that is highly selective for the amidation of benzylic C-H bonds controlled by π-πinteractions in the secondary coordination sphere. Mechanistic understanding of the previously developed iridium catalysts that showed poor regioselectivity gave rise to the recognition that the π-cloud of an aromatic fragment on the substrate can act as a formal directing group through an attractive noncovalent interaction with the bidentate ligand of the catalyst. On the basis of this mechanism-driven strategy, we developed a cationic (ν5-C5H5)Ru(II) catalyst with a neutral polypyridyl ligand to obtain record-setting benzylic selectivity in an intramolecular C-H lactamization in the presence of tertiary C-H bonds at the same distance. Experimental and computational techniques were integrated to identify the origin of this unprecedented benzylic selectivity, and robust linear free energy relationship between solvent polarity index and the measured site-selectivity was found to clearly corroborate that the solvophobic effect drives the selectivity. Generality of the reaction scope and applicability toward versatile γ-lactam synthesis were demonstrated.
Structure-Odor Relationships of (Z)-3-Alken-1-ols, (Z)-3-Alkenals, and (Z)-3-Alkenoic Acids
Lorber, Katja,Zeh, Gina,Regler, Johanna,Buettner, Andrea
, p. 2334 - 2343 (2018/03/21)
(Z)-3-Unsaturated volatile acids, alcohols, and aldehydes are commonly found in foods and other natural sources, playing a vital role in the attractiveness of foods but also as compounds with chemocommunicative function in entomology. However, a systematic investigation of their smell properties, especially regarding humans, has not been carried out until today. To close this gap, the odor thresholds in air and odor qualities of homologous series of (Z)-3-alken-1-ols, (Z)-3-alkenals, and (Z)-3-alkenoic acids were determined by gas chromatography-olfactometry. It was found that the odor qualities in the series of the (Z)-3-alken-1-ols and (Z)-3-alkenals changed, with increasing chain length, from grassy, green to an overall fatty and citrus-like, soapy character. On the other hand, the odor qualities of the (Z)-3-alkenoic acids changed successively from cheesy, sweaty via plastic-like, to waxy in their homologous series. With regard to their odor potencies, the lowest thresholds in air were found for (Z)-3-hexenal, (Z)-3-octenoic acid, and (Z)-3-octenal.
One-Step Bioconversion of Fatty Acids into C8-C9 Volatile Aroma Compounds by a Multifunctional Lipoxygenase Cloned from Pyropia haitanensis
Zhu, Zhu-Jun,Chen, Hai-Min,Chen, Juan-Juan,Yang, Rui,Yan, Xiao-Jun
, p. 1233 - 1241 (2018/02/19)
The multifunctional lipoxygenase PhLOX cloned from Pyropia haitanensis was expressed in Escherichia coli with 24.4 mg·L-1 yield. PhLOX could catalyze the one-step bioconversion of C18-C22 fatty acids into C8-C9 volatile organic compounds (VOCs), displaying higher catalytic efficiency for eicosenoic and docosenoic acids than for octadecenoic acids. C20:5 was the most suitable substrate among the tested fatty acids. The C8-C9 VOCs were generated in good yields from fatty acids, e.g., 2E-nonenal from C20:4, and 2E,6Z-nonadienal from C20:5. Hydrolyzed oils were also tested as substrates. The reactions mainly generated 2E,4E-pentadienal, 2E-octenal, and 2E,4E-octadienal from hydrolyzed sunflower seed oil, corn oil, and fish oil, respectively. PhLOX showed good stability after storage at 4 °C for 2 weeks and broad tolerance to pH and temperature. These desirable properties of PhLOX make it a promising novel biocatalyst for the industrial production of volatile aroma compounds.
Method for asymmetric synthesis of (R)-jasmine lactone
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Paragraph 0020-0022, (2017/08/31)
The invention discloses a method for asymmetric synthesis of (R)-jasmine lactone. The method comprises the steps: oxidating (Z)-3-hexen-1-ol 1, which serves as a starting raw material, with a DMP reagent, so as to obtain (Z)-3-hexenoic aldehyde 2; then, carrying out an asymmetric addition reaction with methyl alkyne-butyrate in the presence of a (R,R)-ProPhenol ligand and zinc methyl, so as to obtain (S,Z)-5-hydroxyl-7-decen-3-methyl acetylenate 3; reducing a triple bond into a single bond with NaBH4 in the presence of CuI, so as to produce (R,Z)-5-hydroxyl-7-methyl decenoate 4; and finally, carrying out treatment with para-toluenesulfonic acid, and carrying out ring closing, thereby obtaining the target product, i.e., (R)-jasmine lactone. According to the method, the synthesis route is simple and direct, the reaction conditions are mild, the total yield is 42%, and the optical purity of the product is 95%.
Characterization of Aroma-Active Compounds in Italian Tomatoes with Emphasis on New Odorants
Kreissl, Johanna,Schieberle, Peter
, p. 5198 - 5208 (2017/07/04)
An aroma distillate was prepared by solvent extraction and subsequent SAFE distillation from Italian vine-ripe tomatoes eliciting an intense overall aroma. Application of gc/olfactometry and the aroma extract dilution analysis revealed 44 odor-active compounds, 42 of which could be identified. The highest odor activity value of 2048 was established for the green, grassy (Z)-3-hexenal, the metallic smelling trans-4,5-epoxy-(E)-2-decenal, the potato-like 3-(methylthio)propanal, and the caramel-like 4-hydroxy-2,5-dimethyl-3(2H)-furanone. Of the further odorants, 13 compounds have previously not been reported as tomato odorants. Although most of these showed lower FD-factors, in particular, the coconut/dill-like smelling wine lactone ((3S,3aS,7aR)-3a,4,5,7a-tetrahydro-3,6-dimethylbenzofuran-2(3H)-one) appeared with a quite high FD factor. In addition, a fruity, almond-like odorant (6) with an FD factor of 1024 was detected. By application of high resolution mass spectrometry and polarity considerations, the structure of a methyl-2-ethoxytetrahydropyran isomer was suggested for 6. Four of the five possible isomers, the 3-methyl-, 4-methyl-, 5-methyl-, and 6-methyl-2-ethoxytetrahydropyran were synthesized and showed similar mass spectrometric patterns. However, these were excluded by their different retention indices. Although the synthesis of the remaining 2-methyl-2-ethoxytetrahydropyran resulted in only small yields, which were not sufficient for NMR measurements, this structure is very likely for 6. This compound was never reported as a food constituent before. Finally, quantitation of 23 odorants by stable isotope dilution assays allowed for the preparation of an aroma recombinate resembling the overall aroma of the tomatoes.
Identification of (Z)-3:(E)-2-Hexenal isomerases essential to the production of the leaf aldehyde in plants
Kunishima, Mikiko,Yamauchi, Yasuo,Mizutani, Masaharu,Kuse, Masaki,Takikawa, Hirosato,Sugimoto, Yukihiro
, p. 14023 - 14033 (2016/07/11)
The green odor of plants is characterized by green leaf volatiles (GLVs) composed of C6 compounds. GLVs are biosynthesized from polyunsaturated fatty acids in thylakoid membranes by a series of enzymes. A representative member of GLVs (E)-2-hexenal, known as the leaf aldehyde, has been assumed to be produced by isomerization from (Z)-3-hexenal in the biosynthesis pathway; however, the enzyme has not yet been identified. In this study, we purified the (Z)-3:(E)-2-hexenal isomerase (HI) from paprika fruits and showed that various plant species have homologous HIs. Purified HI is a homotrimeric protein of 110 kDa composed of 35-kDa subunits and shows high activity at acidic and neutral pH values. Phylogenetic analysis showed that HIs belong to the cupin superfamily, and at least three catalytic amino acids (His, Lys, Tyr) are conserved in HIs of various plant species. Enzymatic isomerization of (Z)-3-hexenal in the presence of deuterium oxide resulted in the introduction of deuterium at the C4 position of (E)-2-hexenal, and a suicide substrate 3-hexyn-1-al inhibited HI irreversibly, suggesting that the catalytic mode of HI is a keto-enol tautomerism reaction mode mediated by a catalytic His residue. The gene expression of HIs in Solanaceae plants was enhanced in specific developmental stages and by wounding treatment. Transgenic tomato plants overexpressing paprika HI accumulated (E)-2-hexenal in contrast to wild-type tomato plants mainly accumulating (Z)-3-hexenal, suggesting that HI plays a key role in the production of (E)-2-hexenal in planta.
Hydroformylation of piperylene and efficient catalyst recycling in propylene carbonate
Neubert, Peter,Fuchs, Sarah,Behr, Arno
, p. 4045 - 4052 (2015/07/15)
In contrast to monoolefins, diene hydroformylation is still a demanding task. Some dienes like butadiene and isoprene have been investigated more intensively, however, 1,3-pentadiene (piperylene) has been rarely investigated. Here, we present a systematic investigation of the hydroformylation of piperylene, using Rh(CO)2acac/Xantphos as an active catalyst which can be easily recycled in the green solvent propylene carbonate. Under the chosen conditions aldehyde yields of up to 82% have been obtained, while catalyst recycling was possible for up to six runs.
Pheromone synthesis. Part 257: Synthesis of methyl (2E,4Z,7Z)-2,4,7-decatrienoate and methyl (E)-2,4,5-tetradecatrienoate, the pheromone components of the male dried bean beetle, Acanthoscelides obtectus (Say)
Mori, Kenji
supporting information, p. 5589 - 5596 (2015/08/03)
Tandem Dess-Martin oxidation/Wittig reaction of (2Z,5Z)-2,5-octadien-1-ol yielded methyl (2E,4Z,7Z)-2,4,7-decatrienoate, a newly discovered pheromone component of the male dried bean beetle, while that of (±)-2,3-dodecadien-1-ol gave (±)-methyl (E)-2,4,5-tetradecatrienoate, the racemate of the known and major pheromone component. Methyl (2E,4E,7Z)-2,4,7-decatrienoate was also synthesized, which is the methyl ester of an acid metabolite of a green alga. Reduction of 2,5-octadiyn-1-ol with Zn-Cu/EtOH cleanly gave (2Z,5Z)-2,5-octadien-1-ol.
