- Stereochemistry of female-specific normonoterpenes, sex pheromone candidates from the acarid mite, Tyreophagus sp. (Astigmata: Acaridae)
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Two normonoterpenes were detected from an unidentified Tyreophagus sp. as new female-specific components. Both planar structures were identified to be 2,6-dimethyl-5-heptenal (1) and 2,6-dimethyl-5-hepten- 1-ol (2) by GC/MS co-chromatography with synthetic 1 and 2. The stereochemistry of 2 was determined to be R by a GC analysis with a chiral column, while that of 1 was presumed to be similar to 2 based on the biosynthetic aspects.
- Shimizu, Nobuhiro,Miwa, Kuniaki,Noge, Koji,Yakumaru, Ryota,Mori, Naoki,Kuwahara, Yasumasa
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Read Online
- Aromatic aldols and 1,5-diketones as optimized fragrance photocages
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Aromatic aldols and 1,5-diketones with abstractable γ-hydrogen atoms are highly photoactive cage molecules for the release of fragrance carbonyl compounds (aldehydes and Michael ketones, respectively). Aldols 3a-d are easily accessible by Mukaiyama addition and are cleaved to form the substrates with high quantum yields under solar radiation. By tuning the properties of the chromophores, a series of δ-damascone cages 5 were developed that can be used for selective and fast (5a,e) or slow (5b,d) release of fragrances under air and solar irradiation. The intermediates of the Norrish II process were observed by laser transient absorption spectroscopy.
- Griesbeck, Axel G.,Hinze, Olga,Goerner, Helmut,Huchel, Ursula,Kropf, Christian,Sundermeier, Uta,Gerke, Thomas
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Read Online
- Semiochemicals of the scarabaeinae. VII: Identification and synthesis of ead-active constituents of abdominal sex attracting secretion of the male dung beetle, Kheper subaeneus
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Using gas chromatography with flame ionization detection (FID) and electroantennographic detection (EAD) in parallel, butanoic acid, skatole, and (E)-2,6-dimethyl-6-octen-2-ol were identified as constituents of the abdominal sex-attracting secretion of the male dung beetle, Kheper subaeneus, which reproducibly elicited EAD responses in male and female antennae. This is the first report of the occurrence of (E)-2,6-dimethyl-6-octen-2-ol as a natural product, for which the name (E)-subaeneol is proposed. In some experiments, a few other constituents of the secretion also gave reproducible responses in specific male and female antennae but did not elicit responses when the analyses were repeated with other antennae. The major volatile constituent of the secretion, identified as (S)-(+)-2,6-dimethyl-5-heptenoic acid, is one of these EAD-active compounds. Both this compound and (E)-2,6-dimethyl-6-octen-2-ol were synthesized from authentic starting materials for comparison with the natural products.
- Burger,Petersen,Weber,Munro
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Read Online
- A New Family of Rigid Dienone Musks Challenges the Perceptive Range of the Human Olfactory Receptor OR5AN1
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A new family of dienone musks was discovered by alkylation of different aldehydes with but-3-en-1-yn-1-yllithium and subsequent domino reaction of a Saucy-Marbet transfer vinylation-Claisen rearrangement with an intramolecular Diels-Alder reaction, and concluding Lewis acid catalyzed double-bond isomerization. The newly synthesized dienone structures possess pleasant musk odors displaying fatty, slightly fruity and green facets. Although the dienone musks were predicted in silico to bind to the OR5AN1 receptor based on QM/MM calculations, they were found to be inactive in the in vitro assay. The latter results suggest that the OR5AN1 receptor is not the prime musk receptor but primarily responsible for the animalic character of certain macrocyclic ketones and nitro musks.
- Emter, Roger,Esposito, Carmen,Hürlimann, Vera,Kraft, Philip,Linker, Stephanie M.,Liu, Jie,Natsch, Andreas,Riniker, Sereina,Wang, Quanrui,Zhou, Lijun,Zou, Yue
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Read Online
- A study towards the synthesis of (-)-atrop-abyssomicin C core
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An attempt to synthesize the cyclohexane core of antibiotic abyssomicin C is described. The initial, protecting group-free approach (relying on internal protection) failed and had to be modified, in order to allow for efficient deprotection of the acid-sensitive cyclization precursor in the penultimate synthetic step. Thus, a pyranoside structural unit was used as a latent lactone/ester functionality, which was deprotected via thioacetalization/hydrolysis/oxidation sequence, to give the δ-valerolactone-type cyclization precursor. Unfortunately, the key cyclization reaction was not feasible, even after structural modification of the cyclization precursor. Reluctance towards cyclization turned out to be a general property of (at least some) Δ7-unsaturated esters, which required the development of a new strategy for this type of transformation.
- Sai?i?, Radomir N.,Trm?i?, Milena
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p. 1305 - 1315
(2022/02/19)
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- Preparation method of epoxy caprylate and preparation method of melonal
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The invention relates to a preparation method of epoxy caprylate and a preparation method of melonal. The preparation method of the epoxy caprylate comprises the steps of in a solvent, in the presence of a first alkaline substance and a first catalyst, carrying out a Darzens reaction on methyl heptenone and alpha-halogenated acetate to obtain a first reaction solution; and separating the first reaction solution to obtain epoxy caprylate, wherein the first catalyst comprises transition metal ions and a Schiff base ligand combined with the transition metal ions, and the structure of the Schiff base ligand is shown in a formula I defined in the description. According to the preparation method of the epoxy caprylate, the raw materials are good in safety, the reaction conditions are mild, melonal is prepared on the basis of the preparation method of the epoxy caprylate, the first reaction solution can be directly subjected to saponification, acidification and decarboxylation reactions without purification, and the prepared melonal has excellent purity and yield.
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Paragraph 0098-0165
(2021/10/30)
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- Process for industrially producing muskmelon aldehyde
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The invention discloses a process for industrially producing muskmelon aldehyde. 1-methyl-3-propylimidazolium hexafluorophosphate ionic liquid is used as a catalyst and a solvent, methyl 3,7-dimethyl-6-ene-2,3-epoxy caprylate is used for obtaining the melonal in one step, and meanwhile, through sectional heating reaction control, the reaction selectivity and the catalytic reaction rate can be improved, the reaction is effectively promoted, and the yield of the melonal is increased and can reach 95% or above. According to the process provided by the invention, the use of hydrogen bromide or hydroiodic acid with strong corrosivity is avoided, the requirements on equipment materials are reduced, the product is easy to separate, the operation is simple and convenient, and the industrial production is facilitated.
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Paragraph 0027-0034
(2020/08/09)
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- Preparation method of muskmelon aldehyde, muskmelon aldehyde and application thereof
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The invention relates to a preparation method of muskmelon aldehyde, muskmelon aldehyde and an application thereof, the preparation method comprises the following steps: carrying out a Darzen condensation reaction on 6-methyl-5-heptene-2-ketone, chloroacetate and an acid-binding agent under the condition of adding a solvent and a phase transfer catalyst to obtain epoxy caprylate; and saponifying the obtained epoxy caprylate in an aqueous solution of alkali to generate corresponding salt, acidifying with acid to obtain 3, 7-dimethyl-6-ene-2, 3-epoxy caprylic acid, carrying out a reduced pressure decarboxylation reaction on 3, 7-dimethyl-6-ene-2, 3-epoxy caprylic acid, and adding a mixture composed of an antioxidant and a polymerization inhibitor to obtain the muskmelon aldehyde product. Theconditions of the preparation method are easier to control, the production is safer, the yield is higher, and the product purity is high.
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- PROCESS FOR THE MANUFACTURE OF 2,6-DIMETHYL-5-HEPTEN-1-AL
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The present invention relates to an improved process for the manufacture of 2,6-dimethyl-5-hepten-1-al.
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Page/Page column 9
(2018/04/30)
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- Method for preparing melonal
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The invention discloses a method for preparing melonal. Under the action of hydroiodic acid or hydrobromic acid, 3,7-dimethyl-6-alkene-2,3-epoxy methyl caprylate reacts, thereby acquiring the melonal. According to the invention, hydroiodic acid or hydrobromic acid is used for replacing the alkaline condition in the prior art, the hydrolysis is directly performed and the melonal is acquired in one step through epoxy acid methyl ester, and the steps of acidification and decarboxylation are omitted, so that the operation is simple, the waste salt problem of the prior art is avoided, the equipment investment is lowered and the method is convenient for industrial production.
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Paragraph 0012; 0031; 0032; 0033; 0034; 0035
(2017/06/02)
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- Biocatalytic Characterization of Human FMO5: Unearthing Baeyer-Villiger Reactions in Humans
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Flavin-containing mono-oxygenases are known as potent drug-metabolizing enzymes, providing complementary functions to the well-investigated cytochrome P450 mono-oxygenases. While human FMO isoforms are typically involved in the oxidation of soft nucleophiles, the biocatalytic activity of human FMO5 (along its physiological role) has long remained unexplored. In this study, we demonstrate the atypical in vitro activity of human FMO5 as a Baeyer-Villiger mono-oxygenase on a broad range of substrates, revealing the first example to date of a human protein catalyzing such reactions. The isolated and purified protein was active on diverse carbonyl compounds, whereas soft nucleophiles were mostly non- or poorly reactive. The absence of the typical characteristic sequence motifs sets human FMO5 apart from all characterized Baeyer-Villiger mono-oxygenases so far. These findings open new perspectives in human oxidative metabolism.
- Fiorentini, Filippo,Geier, Martina,Binda, Claudia,Winkler, Margit,Faber, Kurt,Hall, Mélanie,Mattevi, Andrea
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p. 1039 - 1048
(2016/05/19)
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- PROCESS FOR THE PRODUCTION OF 2,6-DIMETHYLHEPT-5-ENAL BY BAEYER-VILLIGER OXIDATION
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Disclosed is a process for the production of 2,6-dimethylhept-5-enal by Baeyer-Villiger oxidation of 3,7-dimethylocta-2,6-dienal in the presence of aqueous H2O2 and SeO2, followed by hydrolysis.
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Paragraph 0028
(2017/01/31)
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- PROCESS
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Disclosed is a process for the production of 2, 6-dimethylhept-5-enal by Baeyer-Villiger oxidation of 3, 7-dimethylocta-2, 6-dienal in the presence of potassium peroxymonosulfate suspended in a solvent selected followed by hydrolysis.
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Page/Page column 7
(2016/05/02)
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- PERFUME SYSTEMS
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The present application relates to perfume raw materials, perfume delivery systems and consumer products comprising such perfume raw materials and/or such perfume delivery systems, as well as processes for making and using such perfume raw materials, perfume delivery systems and consumer products. Such perfume raw materials and compositions, including the delivery systems, disclosed herein expand the perfume communities' options as such perfume raw materials can provide variations on character and such compositions can provide desired odor profiles.
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Page/Page column 56
(2015/12/08)
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- PROCESS FOR THE PRODUCTION OF 2,6-DIMETHYLHEPT-5-ENAL BY BAEYER-VILLIGER OXIDATION
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Disclosed is a process for the production of 2,6-dimethylhept-5-enal by Baeyer-Villiger oxidation of 3,7-dimethylocta-2,6-dienal in the presence of aqueous H2O2 and SeO2, followed by hydrolysis.
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Page/Page column 4-5
(2015/08/06)
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- Process for the Oxidation of Organic Carbonyl Compounds
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A process for the oxidation of an organic carbonyl compound comprising reacting the organic carbonyl compound, optionally in the presence of a solvent, with hydrogen peroxide in the presence of a catalyst comprising a tin-containing zeolitic material having an MWW-type framework structure.
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Paragraph 0214-0215
(2014/05/20)
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- Total synthesis and biological evaluation of (-)-atrop-abyssomicin C
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Enantioselective synthesis of a marine antibiotic (-)-atrop-abyssomicin C was accomplished in 21 steps, in 1.8% overall yield (4%, based on the recovered starting material). The key steps of the synthesis are the formation of the functionalized cyclohexane core by an organocatalyzed Tsuji-Trost reaction, the formation of a tricyclic spirotetronate unit by a gold-catalyzed reaction sequence and the highly efficient eleven-membered ring closure by a Nozaki-Hiyama-Kishi reaction. Biological tests showed all abyssomicin derivatives to possess strong antibacterial activity against methicillin resistant S. aureus strains; however, they also proved to be cytotoxic, both to malignant and to normal somatic cells. The Royal Society of Chemistry.
- Bihelovic, Filip,Karadzic, Ivanka,Matovic, Radomir,Saicic, Radomir N.
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supporting information
p. 5413 - 5424
(2013/09/02)
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- Total synthesis of (-)-atrop-abyssomicin C
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Rolling in the deep: An enantioselective synthesis of a marine antibiotic (-)-atrop-abyssomicin C (see scheme) is described. The key steps of the synthetic sequence are the application of dual catalysis in the formation of the cyclohexane core, the gold-catalyzed formation of a tricyclic spirotetronate unit, and a highly efficient eleven-membered ring closure by a Nozaki-Hiyama-Kishi reaction. Copyright
- Bihelovic, Filip,Saicic, Radomir N.
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supporting information; experimental part
p. 5687 - 5691
(2012/07/01)
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- Composition of the cloacal gland secretion of tuatara, Sphenodon punctatus
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The lipophilic content of the cloacal gland secretion of the tuatara (Sphenodon punctatus) was investigated. GC/EI-MS Analysis of CH2Cl2 extracts of the secretions revealed triacylglycerols as major glandular constituents. Twelve major medium-chain fatty acids were found to be conjugated to glycerol in different combinations, resulting in complex mixtures. These acids were identified by transesterification and subsequent derivatization of natural samples, and their structures were verified by synthesis. The natural glycerides contain predominantly three of the following acids: octanoic (A), (E)- and (Z)-oct-4-enoic (B and C, resp.), (4E,6Z)-octa-4,6-dienoic (tuataric acid;D), (R)-2,6-dimethylheptanoic (E), (R)-2,6-dimethylhept-5-enoic (F), (Z)-dec-4-enoic (G), (4Z,7Z)-deca-4,7-dienoic (H), (R)-3,7-dimethyloct-6-enoic (I), (R)-4,8-dimethylnon-7-enoic (J), (2R,6S)-2,6,10-trimethylundec-9-enoic (K), and (2R,5E)-2,6,10-trimethylundeca-5,9-dienoic acids (L). Several additional acids, occurring in trace amounts only, were tentatively identified by MS. The elucidation of the absolute configuration of the acids was performed by GC on chiral phases. Individual tuatara show specific mixtures of glycerides with up to 100 components. The individual mixtures may permit individual recognition because the bouquets seem to be stable over years.
- Flachsbarth, Birte,Fritzsche, Matthias,Weldon, Paul J.,Schulz, Stefan
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experimental part
p. 1 - 37
(2010/04/23)
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- Zirconium-catalyzed asymmetric carboalumination of alkenes: ZACA-lipase-catalyzed acetylation synergy
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ZACA-lipase-catalyzed acetylation tandem reactions provide highly efficient and selective routes to either (R)- or (S)-2-methyl-1-alkanols, making, for the first time, the ZACA-based asymmetric synthesis of 2-methyl-1-alkanols widely applicable and satisfactory.
- Huang, Zhihong,Tan, Ze,Novak, Tibor,Zhu, Gangguo,Negishi, Ei-Ichi
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p. 539 - 545
(2008/02/08)
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- Enantioselective total synthesis of (-)-curcuquinone via regioselective chromium-mediated benzannulation
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(Chemical Equation Presented) A short and efficient, high-yielding enantioselective total synthesis of the marine natural product (-)-curcuquinone 1 is reported involving a regioselective [3 + 2 + 1]-benzannulation reaction as the key step. Additionally, this strategy allows the isolation of curcuhydroquinone monomethyl ether 9 as an intermediate of the benzannulation reaction and its subsequent further protection toward diversified hydroquinones.
- Minatti, Ana,Doetz, Karl Heinz
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p. 3745 - 3748
(2007/10/03)
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- A new, alternative, halogen-free synthesis for the fragrance compound Melonal using zeolites and mesoporous materials as oxidation catalysts
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At present Melonal (2,6-dimethyl-5-hepten-1-al) fragrance is industrially produced by a Darzens reaction from 6-methyl-5-hepten-2-one, with ethylchloroacetate as reagent. We present here a novel halogen-free synthesis strategy that involves the chemoselective oxidation of Citral (3,7-dimethyl-6-octen-1-al), a common compound in the fragrance industry, with H2O2 and Sn-Beta or Sn-MCM-41 as catalysts. The performance of tin Lewis acid sites is compared with other potential catalytic sites, and it is found that aluminium Bronsted acid sites and zirconium or titanium Lewis acid sites are less efficient and selective than Sn. In the case of Ti, epoxidation by-products could be found. The re-usability of Sn-Beta zeolite is discussed, as is the heterogeneity of the reaction.
- Corma, Avelino,Iborra, Sara,Mifsud, Maria,Renz, Michael
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- On the radical Brook rearrangement. Reactivity of α-silyl alcohols, α- silyl alcohol nitrite esters, and β-haloacylsilanes under radical-forming conditions
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Two alkoxyl radical generation methods, lead tetraacetate treatment of alcohols and photolysis of nitrites, were applied to α-silyl alcohols 21 and to the corresponding nitrites 25 with a view to forming α-silyl alkoxyl radicals 23 and studying their possible radical Brook rearrangement to α- silyloxy carbon radicals 24. LTA treatment of 21 led to their quick and efficient conversion into mixed acetyl-silyl acetals 33 under very mild conditions. Photolysis of α-alkylmonosubstituted α-silyl nitrites 25 to the corresponding aldehydes is considered to proceed through α-silyl alkoxyl radical intermediates 23. A concerted process is, however, proposed for the case of the benzyl nitrites analogues. On the basis of these results, it is postulated that resonance stabilization can have a major influence on the evolution of α-silyl alkoxyl radicals: should this stabilization be possible, they quickly evolve by α-silyl fragmentation; otherwise, they tend to undergo radical Brook rearrangement. It was also found that the radical Brook rearrangement of α-silyl cyclopropyloxyl radicals generated from β- bromoacylsilanes under standard tin-radical conditions is too slow to compete with β-fragmentation.
- Paredes,Alonso
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p. 2292 - 2304
(2007/10/03)
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- Nickel-catalyzed generation of 2-methylhex-5-enyl ethers from allyl ethers with trimethylaluminium
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Allyl ethers have been converted into the corresponding 2-methylhex-5-enyl ethers in one step on treatment with trimethylaluminium in the presence of a catalytic amount of (dppp)NiCl2.
- Taniguchi, Takahiko,Ogasawara, Kunio
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p. 1531 - 1532
(2007/10/03)
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- Total synthesis of the serine/threonine-specific protein phosphatase inhibitor tautomycin
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A convergent, asymmetric synthesis of the protein phosphatase inhibitor, tautomycin, is described. The natural product was constructed by joining two major fragments of comparable complexity at the C21-C22 bond. Absolute stereochemistry of the C1-C21 ketone originates from (S)-citronellene and (2R,3S)-geraniol epoxide. The anti stereochemical relationships at C6-C7 and C18-C19 were introduced with Duthaler's chiral titanium propionic enolate. Syn stereochemical relationships at C13-C14 and C23-C24 were established using an Evan's oxazolidinone chiral auxiliary. The spiroketal was efficiently constructed via a one-pot double-alkylation-spirocyclization sequence with acetone N,N-dimethylhydrazone serving as the central linchpin. Final coupling of the two halves using a chelation-controlled Mukaiyama aldol addition followed by deprotection yielded synthetic tautomycin that is identical to the natural product.
- Sheppeck II, James E.,Liu, Wen,Chamberlin, A. Richard
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p. 387 - 398
(2007/10/03)
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- ASYMMETRIC SYNTHESIS VIA HETEROCONJUGATE ADDITION USING ELIEL'S CAMPHOR TEMPLATE
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A new asymmetric synthesis is reported that includes carbon-carbon bond formation based upon heteroconjugate addition with Eliel's 1R-(+)-camphor derivative as a template.This method showed high enantiomeric excess under chelation control affected by the solvent polarity and by the salt present in the reaction media. (+)-citronellal was synthesized as a proof of this method.
- Isobe, Minoru,Obeyama, Junko,Funabashi, Yasunori,Goto, Toshio
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p. 4773 - 4776
(2007/10/02)
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- Stereoselective formation of a cyclopentanoid with three contiguous substituents via intramolecular cycloaddition
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A stereoselective formation of a cyclopentanoid with three contiguous substituents has been demonstrated by using a linear aldehyde and Meldrum's acid via an intramolecular cycloaddition
- Takano, Seiichi,Satoh, Shigeki,Ogasawara, Kunio
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- Process for preparing 6-hydroxy-2,6-dimethylheptanal and intermediates thereof
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Described is the compound 6-hydroxy-2,6-dimethylheptanal useful in augmenting or enhancing the aroma or taste of foodstuffs, flavoring compositions for foodstuffs, tobacco compositions, flavoring compositions for tobacco, perfume compositions, ingredients for perfume compositions, perfumed articles and ingredients for perfumed articles as well as a process for preparing 6-hydroxy-2,6-dimethylheptanal comprising the steps of: (i) forming a sulfite addition salt of 2,6-dimethyl-5-heptenal by mixing an alkali metal sulfite in boric acid with 2,6-dimethyl-5-heptenal and (ii) hydrating the thus formed 2,6-dimethyl-5-heptenal sulfite addition salt with a hydrating reagent as well as the intermediate which is the sulfite addition salt of 2,6-dimethyl-5-heptenal.
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