- The Sex Attractant Pheromone of Male Brown Rats: Identification and Field Experiment
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Trapping brown rats is challenging because they avoid newly placed traps in their habitat. Herein, we report the identification of the sex pheromone produced by male brown rats and its effect on trap captures of wild female brown rats. Collecting urine- and feces-soiled bedding material of laboratory-kept rats and comparing the soiled-bedding odorants of juvenile and adult males, as well as of adult males and females, we found nine compounds that were specific to, or most prevalent in, the odor profiles of sexually mature adult males. When we added a synthetic blend of six of these compounds (2-heptanone, 4-heptanone, 3-ethyl-2-heptanone, 2-octanone, 2-nonanone, 4-nonanone) to one of two paired food-baited trap boxes, these boxes attracted significantly more laboratory-strain female rats in laboratory experiments, and captured ten times more wild female rats in a field experiment than the corresponding control boxes. Our data show that the pheromone facilitates captures of wild female brown rats. The male brown rat marks his territory with urine deposits, thereby deterring potential male intruders while retaining females within his deme and attracting wandering females to it. The urine-derived sex pheromone comprises several ketones (2-heptanone, 4-heptanone, 3-ethyl-2-heptanone, 2-octanone, 2-nonanone, 4-nonanone), which when added to baited traps increase the captures of female rats by a factor of ten.
- Takács, Stephen,Gries, Regine,Zhai, Huimin,Gries, Gerhard
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- 3. 7 - Diethyl - 4, 6 - dione preparation method of the nonane (by machine translation)
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The present invention provides a 3, 7 - diethyl nonane - 4, 6 - dione, which belongs to the technical field of compound preparation method, the invention will be benzo triazole with 2 - ethyl butyl chloride reaction to obtain 1 - benzo triazole - 2 - ethyl - 1 - butanone, then the 2 - ethyl butyrate and N, N' - carbonyl imidazole reaction system with dimethyl hydroxylamine hydrochloride and triethylamine mixing and stirring of the reaction system, to obtain the 2 - ethyl - N - methoxy - N - butyl amide, the reactant in the low-temperature conditions and methyl bromide of magnesium oxide to obtain the 3 - ethyl - 2 - pentanone, will 1 - benzo triazole - 2 - ethyl - 1 - butanone with catalyst is dissolved in a solvent, slowly dropping 3 - ethyl - 2 - pentanone, stirring at the room temperature, post-processing to obtain the target product 3, 7 - diethyl nonane - 4, 6 - dione. The invention has the raw materials are easy, and the production cost is low, the product yield is high, the advantage of simple operation. (by machine translation)
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Paragraph 0028; 0031
(2019/04/18)
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- Copper(I)-Catalyzed Enantioselective Nucleophilic Borylation of Aliphatic Ketones: Synthesis of Enantioenriched Chiral Tertiary α-Hydroxyboronates
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A new method was developed for the first catalytic enantioselective borylation of aliphatic ketones. A variety of substrates reacted efficiently with bis(pinacolato)diboron in the presence of a copper(I)/chiral N-heterocyclic carbene complex catalyst to furnish optically active tertiary α-hydroxyboronates with moderate to high enantioselectivities (up to 94 % ee). Notably, the product could be converted into the chiral tertiary alcohol derivative using a stereospecific boron functionalization process. The theoretical study of the mechanism for the enantioselectivity is also described.
- Kubota, Koji,Osaki, Shun,Jin, Mingoo,Ito, Hajime
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supporting information
p. 6646 - 6650
(2017/05/29)
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- Mixed La-Li heterobimetallic complexes for tertiary nitroaldol resolution
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Full details of the kinetic resolution of tertiary nitroaldols derived from simple ketones are described. Mixed BINOL/biphenol La-Li heterobimetallic complexes gave the best selectivity in retro-nitroaldol reactions of racemic tertiary nitroaldols. Using
- Hara, Keiichi,Tosaki, Shin-ya,Gnanadesikan, Vijay,Morimoto, Hiroyuki,Harada, Shinji,Sugita, Mari,Yamagiwa, Noriyuki,Matsunaga, Shigeki,Shibasaki, Masakatsu
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scheme or table
p. 5030 - 5036
(2009/12/03)
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- Mixed La-Li heterobimetallic complexes for tertiary nitroaldol resolution
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A kinetic resolution of tertiary nitroaldols derived from simple ketones is described. Mixed BINOL/biphenol La-Li heterobimetallic complexes gave the best selectivity in retro-nitroaldol reactions of racemic tertiary nitroaldols. By using a mixture of La-Li3-(1a)3 complex (LLB 2a) and La-Li3-(1b)3 (LLB* 2b) complex in a ratio of 2/1, chiral tertiary nitroaldols were obtained in 80-97% ee and 30-47% recovery yield. Copyright
- Tosaki, Shin-Ya,Hara, Keiichi,Gnanadesikan, Vijay,Morimoto, Hiroyuki,Harada, Shinji,Sugita, Mari,Yamagiwa, Noriyuki,Matsunaga, Shigeki,Shibasaki, Masakatsu
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p. 11776 - 11777
(2007/10/03)
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- Thermolysis of 3-alkyl-3-methyl-1,2-dioxetanes: Activation parameters and chemiexcitation yields
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3-Methyl-3-(3-pentyl)-1,2-dioxetane 1 and 3-methyl-3-(2,2-dimethyl-1-propyl)-1,2-dioxetane 2 were synthesized in low yield by the α-bromohydroperoxide method. The activation parameters were determined by the chemiluminescence method (for 1 ΔH? = 25.0 ± 0.3 kcal/mol, ΔS? = -1.0 entropy unit (e.u.), ΔG? = 25.3 kcal/mol, k1 (60°C) = 4.6 × 10-4s-1; for 2 ΔH? = 24.2 ± 0.2 kcal/mol, ΔS? = -2.0 e.u., ΔG? = 24.9 kcal/mol, k1 (60°C) = 9.2 × 10-4s-1. Thermolysis of 1-2 produced excited carbonyl fragments (direct production of high yields of triplets relative to excited singlets) (chemiexcitation yields for 1: φT = 0.02, φS ≤ 0.0005; for 2: φT = 0.02, φS ≤ 0.0004). The results are discussed in relation to a diradical-like mechanism.
- Baumstark, Alfons L.,Anderson, Sean L.,Sapp, Chariety J.,Vasquez, Pedro C.
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p. 176 - 179
(2007/10/03)
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- Thermolysis of 3-alkyl-3-methyl-1,2-dioxetanes: Activation parameters and chemiexcitation yields
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3-Methyl-3-(3-pentyl)-1,2-dioxetane 1 and 3-methyl-3-(2,2-dimethyl-1-propyl)-1,2-dioxetane 2 were synthesized in low yield by the α-bromohydroperoxide method. The activation parameters were determined by the chemiluminescence method (for 1 ΔH? = 25.0 ± 0.3 kcal/mol, ΔS? = -1.0 entropy unit (e.u.), ΔG? = 25.3 kcal/mol, k1 (60°C) = 4.6 × 10-4s-1. Thermolysis of 1-2 produced excited carbonyl fragments (direct production of high yields of triplets relative to excited singlets) (chemiexcitation yields) for 1: φT = 0.2, φ ≤ 0.0005; for 2: φT = 0.02 φS ≤ 0.0004). The results are discussed in relation to a radical-like mechanism.
- Baumstark, Alfons L.,Anderson, Sean L.,Sapp, Chariety J.,Vasquez, Pedro C.
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p. 459 - 462
(2007/10/03)
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- Superacid-catalyzed selective formation-rearrangement of isoalkanes with carbon monoxide to branched ketones
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Efficient high octane oxygenate additives for gasoline, that is, branched aliphatic ketones, are the products of the title reaction of isoalkanes with carbon monoxide. Isobutane, for example, gives methyl isopropyl ketone in 91% yield and 93% selectivity (see scheme). The reaction gives no branched carboxylic acids, showing it to be independent of Koch carbonylation. The intriguing reaction is suggested to proceed through initial electrophilic C-H bond substitution by the formyl cation (or its protosolvated form), followed by rearrangement.
- Olah, George A.,Prakash, G. K. Surya,Mathew, Thomas,Marinez, Eric R.
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p. 2547 - 2548
(2007/10/03)
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- PYROLYTIC FRAGMENTATION AND REARRANGEMENT OF 1-METHOXYCYCLOPROPYLAMINES
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N-Alkyl 2,2-dialkyl-1-methoxycyclopropylamines undergo a pyrolytic fragmentation into alkylisocyanides, methanol, 1,1-dialkylethylenes and novel α,β-unsaturated ketimines.Synthetic methods were developed for the generation of the latter 1-aza-1,3-dienes.
- Kimpe, Norbert de,Buck, Kurt de,Booten, Karl
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p. 393 - 396
(2007/10/02)
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- On the oxidation of 3-ethylpentane under GifIV and Gif-orsay conditions
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The oxidation of 3-ethylpentane under GifIV (and GoAggII) conditions affords, as major product, 3-acetylpentane and not diethylketone as previously reported. The discrepancy is explained by radical chain autoxidation in presence of a weak tertiary C - H bond.
- Barton, Derek H. R.,Doller, Dario,Ozbalik, Nubar,Balavoine, Gilbert,Gref, Aurore,Boivin, Jean
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p. 353 - 356
(2007/10/02)
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- FUNCTIONALISATION OF SATURATED HYDROCARBONS. Part X. A COMPARATIVE STUDY OF CHEMICAL AND ELECTROCHEMICAL PROCESSES (GIF AND GIF-ORSAY SYSTEMS) IN PYRIDINE, IN ACETONE AND IN PYRIDINE-CO-SOLVENT MIXTURES
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Six saturated hydrocarbons (cyclohexane, 3-ethylpentane, methylcyclopentane, cis- and trans-decalin and adamantane) were oxidised by the Gif system (iron catalyst, oxygen, zinc, carboxylic acid) and its electrochemical equivalent (Gif-Orsay system).Results obtained using various solvents (pyridine, acetone, pyridine-acetone mixtures) were similar for both systems.Total or partial replacement of pyridine with acetone affects the selectivity for secondary positions and lowers the ketone/secondary alcohol ratio.The formation of the same ratio of cis- and trans-decal-9-ol from both cis- and trans-decalin clearly demonstrates that tertiary alcohols result from a mechanism essentially radical in nature.
- Belavoine, Gilbert,Barton, Derek H. R.,Boivin, Jean,Gref, Aurore,Coupanec, Pascale Le,et al.
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p. 1091 - 1106
(2007/10/02)
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- Carbanion Rearrangements. Collision-induced Dissociations of Enolate Ions derived from 3-Ethylpentan-2-one
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Reaction of HO- with MeCOCHEt2 produces two enolate ions, MeCOCEt2- and CH2COCHEt2-.The primary carbanion competitively eliminates C2H4 and C4H8, and forms C2HO-.The elimination of C2H4 is a stepwise reaction proceeding through a six-membered transition state; the first step (deprotonation) is rate-determining.The loss of C4H8 is a rearrangement reaction CH2COCHEt2- --> CH2COMe- + EtCH=CH2.The tertiary carbanion competitively eliminates H2, CH4, and C3H8.The losses of CH4 and C3H8 are stepwise processes occuring through six- and five-membered transition state, respectively.A double isotope fractionation experiment shows that both steps of the CH4 elimination are rate-determining.
- Bowie, John H.,Stringer, Michael B.,Currie, Graeme J.
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p. 1821 - 1826
(2007/10/02)
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- DECOMPOSITION OF CARBONATE ESTERS OF 1,3-DIOLS. THE CHEMISTRY OF 1,3-BIFUNCTIONAL SYSTEMS, XXVI
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The decomposition reactions of three cyclic carbonates and, in order to establish the reaction mechanisms, the corresponding diols were studied in presence of KOH, KCN and LiCl.Besides the previously known transformations (fragmentation yielding oxo compounds; CO2 elimination to give oxetanes; fragmentation to olefins), a new reaction of high selectivity has been found.On the action of a large excess of KOH, the carbonate esters of 1,3-diols are transformed into alcohols containing one carbon atom less than the correponding diols.
- Bartok, M.,Molnar, A.,Bartok-Bozoki, G.
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p. 375 - 380
(2007/10/02)
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- 1,2-Bond Shift Isomerization on Copper
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Besides yielding 3-ethyl-3-hydroxypentan-2-one (2) and 3-ethylpentan-2-one (4), 3-ethylpentane-2,3-diol (1) is transformed on copper catalysts into 4-methyl-4-hydroxyhexan-3-one (3) and 4-methylhexan-3-one (5), via 1,2-ethyl migration, this being the first experimental observation of 1,2-bond shift isomerization on copper.
- Bartok, Mihaly,Molnar, Arpad
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p. 1178 - 1180
(2007/10/02)
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- Stereochemistry of Aliphatic Carbocations, 13. Protonated Cyclopropanes as Intermediates in 1,2-Alkyl Shifts
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The nitrous acid deamination of 2-ethyl-1-methylbutylamine (10), 1,2-diethylbutylamine (35), and 2-ethyl-1-methylpentylamine (43) has been studied with respect to 1,2-alkyl shifts.Optically active and deuterated amines were employed whenever possible.The structure, configuration, and deuterium distribution of various products (e. g. 16 from 10, 40 and 48 from 35, 56 from 43) are most reasonably explained in terms of alkyl-bridged intermediates (corner-protonated cyclopropanes) which isomerize via proton shifts from corner to corner.The alternative interconversion of open ions via 1,3-H shifts is incompatible with our experimental results.
- Kirmse, Wolfgang,Loosen, Karin,Prolingheuer, Ernst-Christoph
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p. 129 - 141
(2007/10/02)
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- BIS-β,β'-CONJUGATE ADDITION
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Addition of organocuprates to α,β-enones which possess on the β'-carbon a heteroatom substituent leads in good to excellent yield to β,β'-dialkylated ketones.This process is termed bis-β,β'-conjugate addition.
- Smith, Amos B.,Wexler, Barry A.,Slade, Joel S.
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p. 3237 - 3240
(2007/10/02)
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