- A Microbial Synthesis of R and S-9-Hydroxy-(E)-2-Decenoic Acid(9-HDA), A Queen Honeybee Pheromone
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(R,E)-9-hydroxy-2-decenoic acid (9-HDA) and its (S,E)-isomer have been prepared by using an organic-microbial approach.
- Gu, Jian-Xing,Li, Zu-Yi,Lin, Guo-Qiang
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- Ultrasound-assisted synthesis and in vitro antimicrobial activity of novel 5-oxo-2-pyrrolidinecarboxamides and 7-oxo-2-azepanecarboxamides
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A facile one-pot reaction has been set up for the synthesis of novel 5-oxo-2-pyrrolidinecarboxamides and 7-oxo-2-azepanecarboxamides 4a-j from three-component reaction of keto carboxylic acids 1a-d, various primary amines 2a-b and isocyanides 3a-b under ultrasound irradiation. The present protocol offers attractive characteristics such as easy handling methodology, good-to-excellent yields, environmental friendliness, clean reaction, higher atom economy, convenient operation, and shorter reaction time. The newly synthesized 5-oxo-2-pyrrolidinecarboxamides and 7-oxo-2-azepanecarboxamides 4a-j have been screened for their antimicrobial activity and the majority of these cyclic amides exhibited weak antimicrobial activity.
- Jassem, Ahmed Majeed,Chen, Beining
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- Selective C-C Bond Cleavage of Cycloalkanones by NaNO2/HCl
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A novel selective fragmentation of cycloalkanones by NaNO2/HCl has been established. The C-C bond cleavage reaction proceeds smoothly under mild conditions, selectively affording versatile keto acids or oxime acids. The methodology can streamline the synthesis of valuable chiral molecules and isocoumarins from readily available feedstocks.
- He, Tianyu,Chen, Dengfeng,Qian, Shencheng,Zheng, Yu,Huang, Shenlin
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p. 6525 - 6529
(2021/09/02)
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- Synthesis of α-Tertiary Amine Derivatives by Intermolecular Hydroamination of Unfunctionalized Alkenes with Sulfamates under Trifluoromethanesulfonic Acid Catalysis
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An efficient and mild trifluoromethanesulfonic acid-catalyzed hydroamination of unfunctionalized alkenes to afford α-tertiary amine derivatives at temperatures as low as room temperature is reported. 2,2,2-Trifluoroethyl sulfamate was found to be the optimal nitrogen source because its good solubility in both organic solvents and water facilitated both conversion and purification. The reaction conditions were compatible with a variety of substrate functional groups and afforded moderate to good yields. The desired amine compounds could be obtained easily by means of a mild, one-pot, redox-neutral deprotection procedure. Caryolane amine was synthesized with excellent chemo- and regioselectivities by means of a cascade hydroamination reaction of β-caryophyllene.
- Fei, Jun,Wang, Zhen,Cai, Zheren,Sun, Hao,Cheng, Xu
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supporting information
p. 4063 - 4068
(2016/01/25)
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- Analytical methodology for determination of organic aerosol functional group distributions
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Secondary organic aerosol (SOA) particles result from the condensation of oxidized volatile organic compounds (VOC) and consist of a complex mixture that is not conducive to complete compositional analysis. We present a simple methodology for determining the quantities of aldehydes and ketones, alcohols, and carboxylic acids in such samples via derivatization and high-performance liquid chromatography (HPLC) with ultraviolet-visible absorption detection and tandem mass spectrometry (MS/MS). Useful concentration ranges are presented with an examination of the specificity of these compounds in multiply substituted systems. Such data are valuable in modeling the formation of laboratory-generated aerosols and in identifying point sources of field-collected aerosol samples. Calibration curves on standard samples, MS/MS transitions, including collisionally induced dissociation (CID) products, and a quantitative examination of the specificity of the derivatization reagents toward multiple functional groups are presented for a series of aliphatic standard samples. These methods are then applied to filter extracts from SOA derived from 1-iodooctane photolysis at 254 nm to demonstrate the methodology on a complex system. Ultimately, this methodology enables the measurement of variations in the chemical nature of the oxygen within an SOA particle, providing a distribution of functional group concentrations. This article not subject to U.S. Copyright. Published 2013 by the American Chemical Society.
- Kalafut-Pettibone, Alicia J,McGivern, W. Sean
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p. 3553 - 3560
(2013/05/22)
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- Controlling the photochemical reactions of alkenes by light-path length effects of a microchannel reactor
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Photoirradiation of Me2CO-H2O solution of pent-4-en-1-ol (1a) with a high-pressure mercury lamp in a test tube gave 8-hydroxyoctan-2-one (3a) in 66 % yield along with oxetane (4a) and the isomer (4a') in 10 % yield. Irradiation of the running Me2CO-H2O solution of 1a in the flow system of a microchannel reactor (MCR) gave mainly 4a. The photoreaction of 1,1-diphenylethene (2a) with triethylamine gave a Markovnikov-type adduct (5a) and an anti-Markovnikov-type adduct (6a). The use of the MCR enhanced the production of 5a. These phenomena were explained by the light-path length effects of the MCR.
- Yamashita, Toshiaki,Matsushita, Shuhei,Nagatomo, Takuya,Yamauchi, Ryosuke,Yasuda, Masahide
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p. 111 - 126
(2013/02/25)
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- An efficient iron-catalyzed carbon-carbon single-bond cleavage via retro-claisen condensation: A mild and convenient approach to synthesize a variety of esters or ketones
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An efficient iron-salt-catalyzed carbon-carbon bond cleavage occurring through a retro-Claisen condensation reaction has been developed. The reaction is useful for the synthesis of a variety of esters or ketones under mild conditions. This method works under solvent-free conditions without the need of an inert atmosphere. This protocol is also applicable for the one-pot syntheses of ketones through tandem carbon-carbon bond formation (substitution or Michael) followed by a retro-Claisen reaction. However, for Michael adducts, ring annulation takes place subsequently. Notably, this method is very simple, convenient, high yielding, and only a catalytic (5 to 1.0 mol-%) amount of Fe(OTf)3 is needed.
- Biswas, Srijit,Maiti, Sukhendu,Jana, Umasish
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supporting information; experimental part
p. 2861 - 2866
(2010/08/05)
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- Indium-catalyzed retro-claisen condensation
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(Chemical Equation Presented) Retro-aldol reaction: Indium-catalyzed reaction of a 1,3-diketone with an alcohol proceeds under solvent-free conditions by nucleophilic attack of the alcohol on a carbonyl group of the 1,3-diketone and carbon-carbon bond cleavage by a retro-Claisen condensation to give an ester in high yield (see scheme). Using water and an amine as nucleophiles instead of an alcohol gave the corresponding carboxylic acid and amide.
- Kawata, Atsushi,Takata, Kazumi,Kuninobu, Yoichiro,Takai, Kazuhiko
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p. 7793 - 7795
(2008/09/18)
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- Synthesis of a multifunctional pheromone of the honeybee Apis mellifera via condensation of 7-oxooctanal with malonic acid
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Condensation of 7-oxooctanal with malonic acid in a Doebner reaction produces 9-oxo-2E-decenoic acid (42% yield) and a comparable amount of products from Tishchenko disproportionation of the starting aldehyde (7-oxooctyl-7- oxooctanoate) and re-esterification by acetic acid (7-oxooct-1-ylacetate and 7-oxooctanoic acid).
- Ishmuratov,Yakovleva,Botsman,Ishmuratova,Muslukhov,Khambalova,Tolstikov
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- Arylmethyl esters as protecting groups for carboxylic, carbonic and carbamic acids: Deprotection via homogeneous palladium-catalyzed hydrogenolysis
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4-Quinolylmethyl (4-QUI) esters of carboxylic acids and 1-naphthylmethyl (1-NAP) esters of carbonic and carbamic acids are reduced by palladium-catalyzed hydrogenolysis by formate anion. The reaction conditions are compatible with the presence of a benzyl ester and of an alkene double bond.
- Boutros, Andre,Legros, Jean-Yves,Fiaud, Jean-Claude
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p. 7329 - 7332
(2007/10/03)
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- Halogenated olefins, processes for their preparation and their use as pesticides
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This are described new halogenated olefines of general formula I STR1 in which X1, X2, X3, n and A have the meanings given in the description as well as processes for their preparation. The compounds can be used as pesticides especially against insects and acarids.
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- Direct Synthesis of Carboxylic Acids from Organoboranes
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Direct Synthesis of carboxylic acids through a two carbon atom homologation from organoboranes has been achieved, by the reaction with the dianion of phenoxyacetic acid.It is now possible to synthesize alkanoic, alkenoic, or alkynoic acids, from the corresponding alkenes, dienes, or enynes, respectively, via hydroboration.The reaction is tolerant of various functional groups present in alkenes, thus giving the corresponding carboxylic acids with chloro, sulfide, ether, acetal, and thioacetal functionalities in good yields.
- Hara, Shoji,Kishimura, Kotaro,Suzuki, Akira,Dhillon, Ranjit S.
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p. 6356 - 6360
(2007/10/02)
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- Strategies of Synthesis based on Cyclohexadienes: Part 3. A Novel Route to Macrolide Aromatic Polyketides
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A novel route to macrolide aromatic polyketides, having an alkyl-β-resorcylate skeleton has been developed.A formal synthesis of (+/-)-curvularin (1), and (+/-)-lasiodiplodin (3) involving the preparation of the seco acid (31) and the acyclic precursor (34) using a one pot Alder-Rickert reaction from 1,3-dimethoxycyclohexa-1,3-diene (7) and the long-chain acetylenic dienophiles (10) and (11) is reported.
- Birch, Arthur J.,Mani, Neelakandha S.,Rao, G. S. R. Subba
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p. 1423 - 1427
(2007/10/02)
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- A useful method for preparation of carboxylic acids from terminal alkynes
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Substituted acetic acids can be prepared in good yield (50-80percent) from terminal acetylenes of the same chain length.The alkyne is first converted to the thiophenyl ether, which is treated without purification with mercuric sulfate in acetic acid and 2N sulfuric acid affording the carboxylic acid.The method is particularly useful in the synthesis of long chain ω-hydroxyalkanoic acids.
- Abrams, Suzanne R.
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p. 2423 - 2424
(2007/10/02)
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- Conjugates of Catecholamines. 1. N-Alkyl-Functionalized Carboxylic Acid Congeners and Amides Related to Isoproterenol
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A series of functionalized catecholamines (congeners) has been synthesized in which, formalistically, N-isopropyl group of isoproterenol has been extended by a linear alkyl chain of varying length, terminated by a carboxy group or a substituted amide.The compounds were prepared generally via the reductive amination of norepinephrine with a keto acid or a preformed keto amide.An alternate synthesis of the model amide derivatives, involving activation of the carboxylic acid congeners and coupling with amines, was complicated in the case of short-chain derivatives by facile cyclization to lactams.In vitro evaluation of these compounds as potential β-adrenergic agonists has shown that, while the carboxylic acid congeners have relatively low potencies, the model amide derivatives have potencies that are highly dependent on both the length of the alkyl chain and also the nature of the substituent on the amide.In general, aromatic amides are the most potent, although the nature and position of substituents on the aromatic group dramatically influences their potency.The implications of these studies, in terms of general β-adrenergic drug design and also the attachment of the carboxylic acid congeners to carries, are discussed
- Jacobson, Kenneth A.,Marr-Leisy, Debra,Rosenkranz, Roberto P.,Verlander, Michael S.,Melmon, Kenneth L.,Goodman, Murray
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p. 492 - 499
(2007/10/02)
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- 1'-(6-Hydroxyoctanoyl)nornicotine and 1'-(7-Hydroxyoctanoyl)nornicotine, Two New Alkaloids from Japanese Domestic Tobacco
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Two new pyridine alkaloids were isolated from an extract of air-cured Japanese domestic tobacco (Nicotiana tabacum L. cv.Ibusuki).The assigned structures of 1'-(6-hydroxyoctanoyl)nornicotine (IIb) and 1'-(7-hydroxyoctanoyl)nornicotine (IIc) were based on spectroscopic properties.In addition, the structure assignments were confirmed by synthesis.
- Miyano, Masashi,Yasumatsu, Norio,Matsushita, Hajime,Nishida, Koh
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p. 1029 - 1033
(2007/10/02)
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- SYNTHESIS OF (+/-)-DIMETHYL CURVULARIN BASED ON THE PALLADIUM-CATALYZED CARBONYLATION OF 3,5-DIMETHOXYBENZYL CHLORIDE USING A BUTADIENE TELOMER AS A BUILDING BLOCK
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Palladium -catalyzed carbonylation of 3,5-dimethoxybenzyl chloride (13) with benzyl 7-hydroxyoctanoate (12) afforded benzyl 7-(3,5-dimethoxyphenylacetoxy)octanoate (6) in 70percent yield, which is the precursor of Curvularin (4).The ester (12) was easily prepared from the butadiene telomer obtained by the palladium-catalyzed reaction of butadiene with acetic acid.
- Takahashi, Takashi,Ikeda, Hiroshi,Tsuji, Jiro
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p. 3885 - 3888
(2007/10/02)
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