- Novel catalytic bromolactonization of alkenoic acids using iodobenzene and Oxone
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The novel catalytic reaction for bromolactonization of alkenoic acids is reported. When iodobenzene is used as recyclable catalyst in combination with Oxone as terminal oxidant, the cyclization of various 4-pentenoic acids with sodium bromide is easily carried out in CF3CH2OH at room temperature and giving five-membered bromolactones in good yields.
- He, Yan,Pu, Ye,Shao, Bo,Yan, Jie
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- Study on the bromolactonisation of alkenoic acids with (diacetoxyiodo) benzene
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A study on the bromolactonisation of alkenoic acids is reported. When various pent-4-enoic acids reacted with (diacetoxyiodo)benzene (DIB) and lithium bromide in CH3OH at room temperature, most of the five-membered bromolactones were obtained in good to excellent yields in short times. Some had two diastereoisomers. When but-3-enoic acid and trans-hex-3-enoic acid were treated under the same conditions, only unsaturated lactones were found after workup. When hex-5-enoic acid was subjected to the same conditions, however, the desired six-membered bromolactone was not successfully separated.
- He, Yan,Yang, Zhenping,Yan, Jie
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- Identificaton of the Alarm and Sex Pheromones of the Leaf?Footed Bug, Leptoglossus zonatus (Heteroptera: Coreidae)
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The leaf-footed bug, Leptoglossus zonatus (Heteroptera: Coreidae), is mainly found in maize fields in Brazil. In this work, we elucidated and quantified the volatile compounds from nymphs and adults of L. zonatus. The defensive compounds produced by nymphs are aldehydes and oxo-alkenals, with some compounds showing different proportions between instars. For the first time, 5-ethyl-2(5H)-furanone has been identified as a defensive compound for a species of this family. In adults, the alarm pheromone includes hexanal, 1-hexanol, hexanoic acid, hexyl acetate, and octyl acetate. Males and females produce the same compounds, however, hexanal showed a significant difference between sexes. Gas chromatography (GC) analysis of adult aeration extracts revealed male specific compounds, which attactiveness to females was confirmed through olfactometer bioassays. By using a GC-electroantennographic detector (EAD), it was shown that female antenna presented electrophysiological responses to five components ((Z)-β-ocimene, (Z,Z)-allo-ocimene, decanal, α-trans-bergamotene, and (E)-β-farnesene) from male aeration extracts. In this way, we propose that males are responsible for emission of a sex pheromone in this species.
- Inoue, Katia M.,Vidal, Diogo M.,Saad, Emir B.,Martins, Camila B.C.,Zarbin, Paulo H.G.
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- A facile synthesis of γ-butenolides via cyclization of 3-alkenoic acids with dimethyl sulfoxide and oxalyl bromide
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The combination of dimethyl sulfoxide and oxalyl bromide was used to accomplish the cyclization of 3-alkenoic acids with the aid of a base to afford γ-butenolides, in which bromodimethylsulfonium salt generated in situ was proposed to serve as a Br+ source.
- Ding, Rui,Liu, Yongguo,Liu, Lei,Li, Huimin,Tao, Sichen,Sun, Baoguo,Tian, Hongyu
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supporting information
p. 3001 - 3007
(2019/08/26)
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- Mechanistic Studies on the Anodic Functionalization of Alkenes Catalyzed by Diselenides
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Herein, we present a detailed kinetic and thermodynamic analysis of the anodic allylic esterification of alkenes as well as the bulk application of the anodic amination and esterification of nonactivated alkenes catalyzed by diselenides. The electrochemical study led to a comprehensive picture of the coupled electrochemical and chemical reaction steps. Cyclic voltammetry measurements are consistent with a bimolecular step after initial electrochemical 1e- oxidation of the diphenyl diselenide catalyst, 1a, and therefore we postulate a dimerization of the cation, which reacts very rapidly with the alkene, forming the addition product, i.e. the selenolactone 2a. Subsequent electrochemical oxidation of 2a occurs at a slightly higher potential than initial oxidation of 1a. The second oxidation is also followed by a bimolecular process and we hypothesize a dimerization of the cation, which finally eliminates 1a and protons in the rate-determining step, forming the product. Electrochemical analysis of various catalysts, i.e. nonsterically demanding diaryl diselenides with electron withdrawing and donating substituents, revealed that the oxidation potential of the catalyst and the intermediate can be readily tuned by the substituents, thus, prospectively allowing for a wide application of olefinic and nucleophilic substrates. The substituent pattern at the alkene has a smaller influence on the redox potential of the adduct. Controlled potential electrolysis experiments employing different nucleophiles proved that the reaction can be run electrochemically. The functionalization of unactivated alkenes with N- and O-nucleophiles was successfully demonstrated in several bulk electrolysis experiments, and the products were isolated in good yields.
- Wilken, Mona,Ortgies, Stefan,Breder, Alexander,Siewert, Inke
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p. 10901 - 10912
(2018/11/02)
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- Enantioselective protecting-group-free synthesis of (+)-9,10-dihydroecklonialactone B
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An enantioselective protecting-group-free route to ecklonialactones, C-18 oxylipins isolated from the brown algae, was demonstrated by the synthesis of (+)-dihydroecklonialactone B from (E)-ethyl hex-3-enoate in 17 steps.
- Yassen, Asmaa Said Ali,Ishihara, Jun,Hatakeyama, Susumi
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- Mechanistic and Synthetic Investigations on the Dual Selenium-π-Acid/Photoredox Catalysis in the Context of the Aerobic Dehydrogenative Lactonization of Alkenoic Acids
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The aerobic dehydrogenative lactonization of alkenoic acids facilitated by a cooperative nonmetallic catalyst pair is reported. The title procedure relies on the adjusted interplay of a photoredox and a selenium-π-acid catalyst, which allows for the regiocontrolled construction of five- and six-membered lactone rings in yields of up to 96%. Notable features of this method are pronounced efficiency and practicality, good functional group tolerance, and high sustainability, since ambient air and visible light are adequate for the clean conversion of alkenoic acids into their respective lactones. The title method has been used as a case study to elucidate the general mechanistic aspects of the dual selenium-π-acid/photoredox catalysis. On the basis of NMR spectroscopic, mass spectrometric, and computational investigations, a more detailed picture of the catalytic cycle is drawn and the potential role of trimeric selenonium cations as catalytically relevant species is discussed.
- Ortgies, Stefan,Rieger, Rene,Rode, Katharina,Koszinowski, Konrad,Kind, Jonas,Thiele, Christina M.,Rehbein, Julia,Breder, Alexander
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p. 7578 - 7586
(2017/11/10)
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- A novel one-pot sulfonyloxylactonization of alkenoic acids mediated by hypervalent iodine species generated in situ from ammonium iodide
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A novel and efficient one-pot procedure was designed for the sulfonyloxylactonization of alkenoic acids by the reaction of alkenoic acids with m-chloroperbenzoic acid and sulfonic acids in the presence of a catalytic amount of ammonium iodide in a mixture acetonitrile/2,2,2-trifluoroethanol (4: 1) at room temperature for 24 h, which provided the corresponding sulfonyloxy lactones in moderate-to-good yields. Copyright
- Hu, Jiantao,Zhu, Min,Xu, Yuan,Yan, Jie
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p. 137 - 145
(2014/02/14)
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- Synthetic approach toward cis-disubstituted γ- And δ-lactones through enantioselective dialkylzinc addition to aldehydes: Application to the synthesis of optically active flavors and fragrances
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A versatile and straightforward approach to optically active cis-4,5-disubstituted γ- and δ-lactones by catalytic enantioselective addition of dialkyzincs to cinnamic aldehydes and RCM ring closure has been reported. The synthetic importance of the enantioselective dialkylzinc alkylation of aldehydes has been thus widened. Such an approach has then been employed for the enantioselective synthesis of naturally occurring γ-lactone flavors like (S)-5-ethyl-butanolide (6a) and (4S,5S)-cis-whisky lactone (6b) and extended to the preparation of δ-lactones like (5S,6S)-5-methyl-6-ethylpentanolide (9a), precursor of the pheromone serricornin.
- Pisani, Laura,Superchi, Stefano,D'Elia, Alessandra,Scafato, Patrizia,Rosini, Carlo
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experimental part
p. 5779 - 5784
(2012/09/08)
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- Imidazolium-containing diselenides for catalytic oxidations with hydrogen peroxide and sodium bromide in aqueous solutions
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The design and synthesis of imidazolium-containing diselenides 4a-c is described. The introduction of the N-methylimidazolium group gives freely soluble compounds in water, unlike the majority of common organic diselenides. Catalytic amounts of 4a-c effectively promote bromination of organic substrates using a safe and inexpensive NaBr/H2O2 system in water. Kinetics experiments revealed that the bromination of 4-pentenoic acid has a first-order dependence with respect to both NaBr and H2O2 concentrations The rate of reaction was also sensitive to the pH of the solution. Preparative reactions showed that, compared to 4a, diphenyl diselenide 5 was a poor catalyst and the ionic liquid 1-benzyl-3-methylimidazolium bromide 6 showed no catalytic activity with H2O2 indicating synergy from the combined functionality.
- Alberto, Eduardo E.,Detty, Michael R.,Braga, Antonio L.
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p. 10476 - 10481,6
(2012/12/12)
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- An effective method for the preparation of chlorolactones
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The effective chlorolactonization of alkenoic acids with (diacetoxyiodo)benzene and lithium chloride under mild conditions have been studied. Experiments show that various 4-pentenoic acids react with (diacetoxyiodo)benzene and lithium chloride fluently in CH3OH at room temperature, obtaining five-membered chlorolactones in good yields in short times. Other alkenoic acids, such as 3-butenoic acid and trans 3-hexenoic acid give some more complicated results, and 4-pentynoic acid provides a chloroenol lactone with Z configuration in 40% of yield.
- Zhu, Min,Li, Li,Tong, Jiang Ying,Zhang, Hui
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experimental part
p. 431 - 434
(2012/01/03)
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- Convenient synthesis of 5-alkylfuran-2(5H)-ones
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A convenient synthesis of 5-alkylfuran-2(5H)-ones are described starting from 3-nitropropanoate and aldehydes, promoted by neutral alumina, in 35-60% overall yields, via a condensation-lactonization-elimination pathway. Copyright
- Ma, Jie,Wang, Si Hong,Yin, Yan Bing
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p. 3026 - 3031
(2011/08/22)
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- Pd-catalyzed 5-endo-trig-type cyclization of β,γ-unsaturated carbonyl compounds: An efficient ring closing reaction to give γ-butenolides and 3-pyrrolin-2-ones
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The 5-endo-trig-type cyclization has been performed using a Pd-bis(isoxazoline) catalyst. The present cyclization of β,γ- unsaturated carbonyl compounds gave γ-butenolides and 3-pyrrolin-2-ones in good to excellent yields.
- Bajracharya, Gan B.,Koranne, Priti S.,Nadaf, Rashid N.,Gabr, Randa Kassem Mohamed,Takenaka, Kazuhiro,Takizawa, Shinobu,Sasai, Hiroaki
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supporting information; experimental part
p. 9064 - 9066
(2011/02/16)
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- A novel camphorsulfonyloxylactonization of alkenoic acids
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(Chemical Equation Presented) The novel reaction of [hydroxyl (((+)-10-camphorsulfonyl)oxy)iodo]benzene (1) with alkenoic acids was reported. When 1 reacted with various 4-pentenoic acids in CH3CN, camphorsulfonylactons were obtained in excellent yields in short times, some had two diastereoisomers, whereas 1 reacted with 5-hexenoic acid, giving middle yield of camphorsulfonylacton; however, 3-butenoic and trans-3-hexenoic acids reacted with 1 slowly in CH2Cl2, only unsaturated lactones were provided.
- Zhu, Min,Sun, Na-Bo,Li, He,Yan, Jie
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experimental part
p. 436 - 440
(2010/06/16)
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- An efficient catalytic sulfonyloxylactonization of alkenoic acids using hypervalent iodine(III) reagent
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A novel and efficient catalytic method for sulfonyloxylactonization of alkenoic acids is reported. (Diacetoxyiodo)benzene could be used as a recyclable catalyst in combination with m-chloroperbenzoic acid as an oxidant in the presence of sulfonic acid to
- Yan, Jie,Wang, Hong,Yang, Zhenping,He, Yan
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experimental part
p. 2669 - 2672
(2010/01/07)
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- Iodobenzene-catalysed iodolactonisation using sodium perborate monohydrate as oxidant
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A convenient approach has been developed for iodolactonisation using iodobenzene as catalyst. The active reagent was generated in situ with tetra-n-butylammonium iodide (TBAI) and hypervalent iodine reagent, diacetoxyiodobenzene (PIDA). PIDA, in turn, was generated in situ using a catalytic amount of iodobenzene with sodium perborate monohydrate as the stoichiometric oxidant. A variety of olefinic acids including δ-pentenoic acids, δ-pentynoic acids and δ-hexynoic acid gave high yields of lactones using this methodology.
- Liu, Hongjun,Tan, Choon-Hong
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p. 8220 - 8222
(2008/03/14)
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- Copper catalyzed asymmetric synthesis of chiral allylic esters
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The complex derived from Taniaphos ligand 4 and CuBr?Me2S catalyzes the asymmetric addition of Grignard reagents to 3-bromopropenyl esters 1 to provide allylic esters 2 in high yields and high chemio-, regio-, and enantioselectivities. The work demonstrates that allylic asymmetric alkylation (AAA) can be done on substrates bearing a heteroatom at the γ-position. The method is a practical route to chiral, nonracemic allylic alcohols. The use of functionalized substrates 1 or Grignard reagents leads to more complex products 2, which can be further manipulated as demonstrated in conversion to (S)-5-ethyl-2(5H)-furanone 6 and (S)-benzoic acid-cyclopent-2-enyl ester 7. Copyright
- Geurts, Koen,Fletcher, Stephen P.,Feringa, Ben L.
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p. 15572 - 15573
(2007/10/03)
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- One-pot synthesis of 5-Alkylfuran-2(5H)-ones
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5-Alkylfuran-2(5H)-ones can be efficiently obtained using a one-pot approach, starting from methyl 3-nitropropanoate and aldehydes, in ethyl acetate, with Amberlyst A-21 as catalyst, in 60-90% overall yield. Copyright Taylor & Francis Group, LLC.
- Ma, Jie,Wang, Si Hong,Guan, Rong Tian
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p. 1229 - 1233
(2007/10/03)
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- Odorless diphenyl diselenide and disulfide: Syntheses and applications
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Bis[4-(trimethylsilyl)phenyl]diselenide (3) and bis[4-(trimethylsilyl) phenyl]disulfide (31) are found to be odorless equivalents of the commonly used diphenyl diselenide and diphenyl disulfide, respectively. The diselenide 3 is shown to be useful in the preparation of odorless selenium(II) chloride 26 and selenium(IV) trichloride 28 that follow similar reactivity patterns to their phenyl derivatives and can be stored refrigerated under dry conditions. The corresponding selenium(II) bromide had to be prepared fresh from 3 before use. It is also shown that the trimethylsilyl group in the sulfide products can be protodesilylated quantitatively using TFA. Georg Thieme Verlag Stuttgart.
- Patra, Pranab K.,Shanmugasundaram, Kandasamy,Matoba, Manabu,Nishide, Kiyoharu,Kajimoto, Tetsuya,Node, Manabu
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p. 447 - 457
(2007/10/03)
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- Synthetic studies on himbacine, a potent antagonist of the muscarinic M2 subtype receptor. Part 2: Synthesis and muscarinic M2 subtype antagonistic activity of the novel himbacine congeners modified at the C-3 position of lactone moiety
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With an aim to disclose the convergency and flexibility of our previously explored synthetic route to natural himbacine 1, and moreover, to clarify some novel aspects of the structure-activity relationships of 1, we prepared various structural types of novel himbacine congeners, 3-demethylhimbacine (3-norhimbacine) 2 and 4-epi-3-demethylhimbacine (4-epi-3-norhimbacine) 4-epi-2 and their enantiomers (ent-2 and ent-4-epi-2), 11-methylhimbacine 3, and 3-epihimbacine 4 in optically pure forms by employing our methodology. All of the synthesized congeners correspond to the compounds modified at the C-3 position of γ-lactone moiety involved in 1. Among these congeners, 3-demethylhimbacine (3-norhimbacine) 2 was found to exhibit more potent muscarinic M2 receptor binding affinity than natural 1.
- Takadoi, Masanori,Yamaguchi, Kentaro,Terashima, Shiro
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p. 1169 - 1186
(2007/10/03)
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- Intramolecular oxyselenenylation and deselenenylation reactions in water, conducted by employing polymer-supported arylselenenyl bromide
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After immobilizing arylselenenyl bromide on polymer resin, the oxyselenenylation reaction of olefin was carried out in water. An amphiphilic polymer-supported arylselenenyl bromide was employed, and various intramolecular oxyselenenylation and deselenenylation reactions proceeded smoothly in water in fair chemical yields (up to an 83% yield).
- Fujita, Ken-Ichi,Hashimoto, Shigeru,Oishi, Akihiro,Taguchi, Yoichi
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p. 3793 - 3795
(2007/10/03)
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- Kinetic resolution of racemic lactones by conjugate additions of allylic organolithium species: Direct formation of three contiguous centers with high diastereo- and enantioselectivities
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(Matrix presented) Kinetic resolution of racemic α,β-unsaturated lactones by the organolithium species produced from asymmetric lithiation of N-Boc-N-(p-methoxyphenyl)cinnamylamine provides conjugate addition products with three contiguous stereogenic centers in yields of 62-77% with diastereomeric ratios from 75:25 to >99:1 and enantiomeric ratios for the major diastereomers from 94:6 to 98:2.
- Lim, Sung H.,Beak, Peter
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p. 2657 - 2660
(2007/10/03)
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- A sulfur-containing diselenide as an efficient chiral reagent in asymmetric selenocyclization reactions
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Treatment of the di-2-[(1S)-1-(methylthio)ethyl]phenyl diselenide with bromine and silver triflate afforded the corresponding selenyl triflate which was used in situ as a strongly electrophilic selenium reagent to effect the asymmetric synthesis of oxygen- or nitrogen-containing heterocycles. Cyclic ethers, lactones, lactams or N-protected pyrrolidines have been prepared in good yield with complete regioselectivity and high diastereoselectivity.
- Tiecco, Marcello,Testaferri, Lorenzo,Marini, Francesca,Sternativo, Silvia,Bagnoli, Luana,Santi, Claudio,Temperini, Andrea
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p. 1493 - 1502
(2007/10/03)
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- Efficient catalytic selenolactonization-deselenenylation reactions using various organoselenium catalysts and their application to solid-phase conversion
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Efficient selenolactonization-deselenenylation reaction can be produced by a very small amount of various selenoreagents (i.e. selenocatalysts). The most efficient catalytic conversion (turnover: a maximum of 1340) was performed using N-phenylselenophthalimide (NPSP). Moreover, even employing a polymer-supported selenocatalyst, the catalytic conversion produced a more than adequate turnover.
- Fujita,Taka,Oishi,Ikeda,Taguchi,Fujie,Saeki,Sakuma
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p. 1509 - 1511
(2007/10/03)
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- Highly Enantioselective Synthesis of Both Enantiomers of γ-Substituted Butenolides by Bakers' Yeast Reduction and Lipase-Catalyzed Hydrolysis. Total Synthesis of (3AS,6aS)-Ethisolide, Whisky Lactone, and (-)-Avenaciolide
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Reduction of 3-chloro-4-oxoalkanoates 5 with bakers' yeast gave (4S)-3-chloro-4-hydroxyalkanoates, which were hydrolyzed and dehydrochlorinated to give (γS)-alkylbutenolides with >96% ee. Reduction of 5 with NaBH4 gave syn-3-chloro-4-hydroxyalkanoate 6. Asymmetric hydrolysis of syn-4-chloro-3-hydroxyalkanoate (±)-10 with lipase afforded (3R,4R)-6 and (3S,4S)-10 with high optical purities. Hydrolysis and dehydrochlorination of (3R,4R)-6 gave (γA)-alkylbutenolides with >85% ee. Total syntheses of (3aS,6aS)-ethisolide, whisky lactone, and (-)-avenaciolide from these butenolides are described.
- Tsuboi, Sadao,Sakamoto, Jun-Ichi,Yamashita, Hiroshi,Sakai, Takashi,Utaka, Masanori
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p. 1102 - 1108
(2007/10/03)
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- Acetoxy lactonization of alkenyl acetic acids promoted by ammonium persulfate and trifluoromethanesulfonic acid in acetic acid
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The reactions of substituted 4-pentenoic and 3-butenoic acids with ammonium persulfate in acetic acid, in the presence of trifluoromethanesulfonic acid, gave the products of acetoxy lactonization in good yield.
- Tiecco, Marcello,Testaferri, Lorenzo,Tingoli, Marco
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p. 5351 - 5358
(2007/10/02)
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- Regiochemistry of Palladium(II)assisted oxidative lactonisation reactions
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The Pd(II)-assisted lactonisation of alkenoic acids has been studied. The selectivity, persisting to formation of 5- and 6-membered unsaturated lactones, can be governed by the change of solvent and/or base.
- Annby, Ulf,Stenkula, Magnus,Andersson, Carl-Magnus
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p. 8545 - 8548
(2007/10/02)
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- A New Synthesis of Substituted Butenolides via Cation-Initiated Ring Expansion/Elimination of β-Lactones
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When treated with silver ion, γ-bromo β-lactones, available via bromolactonization, undergo a ring expansion/elimination reaction to afford substituted butenolides.
- Black, T. Howard,Huang, Jianhua
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p. 1411 - 1412
(2007/10/02)
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- Rhodium carbonyl-catalyzed carbonylation of unsaturated compounds V. Cross-hydrocarbonylation of 1-alkyne and ethylene by rhodium carbonyl catalyst modified with phosphines
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In the presence of Rh4(CO)12 catalyst modified with triphenylphosphine the cross-hydrocarbonylation of 1-alkyne (RC2H; R = Me, Et, nPr, nBu, and tBu) and ethylene using 2-propanol as the hydrogen donor gives 3-alkyl-5-ethyl-2(5H)-furanone (4, 44-69percent), along with a small amount of 4-alkyl-5-ethyl-2(5H)-furanone (5, 1-8percent). when acetylene itself is used, γ-caprolactone (6a), which is the hydrogenation product of the expected 5-ethyl-2(5H)-furanone (4a), is obtained.The yield of 6a depends on the nature of the phosphine employed and decreases in the following order: PR3 = P(C6H4F-p)3 > PPh3 > P(C6H4Me-p)3 > P(C6H4OMe-p)3 > PPh2Et > PPhEt2 > PEt3.
- Hong, Pangbu,Mise, Takaya,Yamazaki, Hiroshi
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p. 291 - 300
(2007/10/02)
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- Pure Enantiomers from Retro-Diels-Alder Processes
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Diastereoselective and regioselective transformations of cycloadducts to enantiomerically pure cyclopentadienes are reported.Retro-Diels-Alder processes finally give rise to pure enantiomers in high yield.
- Beckmann, Marion,Hildebrandt, Hinrich,Winterfeldt, Ekkehard
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p. 335 - 345
(2007/10/02)
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- IODINE (III) MEDIATED ACETOXY-LACTONIZATION OF UNSATURATED NITRILES
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4-Pentenenitriles reacted with PhI(OAc)2 in acetic acid, in the presence of 48percent HBF4, at 70 deg C, to afford the dihydro-5-acetoxymethyl-2(3H)-furanones in good yields.Similarly, 3-butenenitriles gave the dihydro-4-acetoxy-2(3H)-furanones, although in lower yields.Parallel experiments showed that, under the same conditions, 4-pentenoic and 3-pentenoic acids reacted much more easily and gave the same acetoxy-lactonization process at room temperature.
- Tiecco, Marcello,Testaferri, Lorenzo,Tingoli, Marco,Bartoli, Donatella
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p. 7139 - 7150
(2007/10/02)
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- Regioselective Alkylation of 2-Trimethylsiloxyfuran; Direct Access to 4-Substituted But-2-en-4-olides
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Primary iodides alkylate 2-trimethylsiloxyfuran in the presence of a molar excess of silver trifluoroacetate to give the 4-alkylbut-2-en-4-olides in 55-81percent yield; as an illustration of the method, the cytotoxic marine sponge constituent, 4-(methoxycarbonylmethyl)but-2-en-4-olide was prepared in 79percent yield in one step.
- Jefford, Charles W.,Sledeski, Adam W.,Boukouvalas, John
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p. 364 - 365
(2007/10/02)
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- HYDROBORATION OF 1-(5-HEXENYL)PIPERIDINE AND trans-1-(3-HEXENYL)PIPERIDINE
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1-(5-Hexenyl)piperidine (Ia) and trans-1-(3-hexenyl)piperidine (Ib) were hydroborated with tetrahydrofuran-borane, diborane in situ, 9-borabicyclononane and triethylamine-borane.The hydroboration products were converted to 1-piperidinylhexanols IIa-IIe by hydrolysis with hydrochloric acid and subsequent oxidation with hydrogen peroxide in an alkaline medium.In addition to the alcohols IIa-IIe, the reaction also gave 1-hexylpiperidine (Ic).In the reactions with diborane in situ and triethylamine-borane, thermal isomerisation of the hydroboration products was also studied.Hydroboration of Ia with triethylamine-borane afforded a mixture of spirocyclic amine-boranes IIIa-IIIc from which 6-(1-piperidinyl)-3-hexylboronic acid hydrochloride (IV) was obtained by hydrolysis with hydrochloric acid.Compounds IIIa-IIIc were slowly decomposed with ethanol to give esters of boronic acids Id-If.The synthesis of compounds Ia and Ib is described.
- Kafka, Stanislav,Kytner, Jan,Silhankova, Alexandra,Ferles, Miloslav
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p. 2035 - 2046
(2007/10/02)
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- CHEMISTRY OF BAKER'S YEAST REDUCTION PRODUCTS: USE OF OPTICALLY ACTIVE (S)-(+)-1-(p-TOLUENESULFONYL)PROPAN-2-OL AND (S)-(+)-1-(PHENYLSULFONYL)PROPAN-2-OL IN SYNTHESIS.
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The utility of the title compounds in the preparation of optically active lactones and alcohols is detailed.
- Kozikowski, Alan P.,Mugrage, B.B.,Li, C.S.,Felder, L.
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p. 4817 - 4820
(2007/10/02)
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- Cyclization of 4-Hydroxy-(E)-2-alkenoic Esters: Simple Synthesis of Butenolides
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Simple treatment of 4-hydroxy-(E)-2-alkenoic esters with benzenethiol leads to cyclization to give 3-phenylthio-4-alkanolides, which are easily converted into 3-phenylthio-2-alken-4-olides and 2-alken-4-olides (Δα,β-butenolides).
- Tanikaga, Rikuhei,Yamashita, Hiroshi,Kaji, Aritsune
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p. 416 - 417
(2007/10/02)
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- TOSYLOXYLACTONIZATION OF ALKENOIC ACIDS WITH BENZENE
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benzene(1) reacts with 3-butenoic, 4-pentenoic, 5-hexenoic and 2-methyl-4-pentenoic acids in CH2Cl2 to give tosyloxyacetones and with trans-3-hexenoic and 2-cyclopenteneacetic acids to give unsaturated lactones. 5-Norbornene-endo-2-carboxylic acid with 1 gives a rearranged lactone while 5-norbornene-endo-2,3-dicarboxylic acid gives a bis-lactone.
- Shah, Mayur,Taschner, Michael J.,Koser, Gerald F.,Rach, Nancy L.
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p. 4557 - 4560
(2007/10/02)
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- A NEW SYNTHESIS OF α,β-UNSATURATED γ- AND δ-LACTONS VIA INTRAMOLECULAR ACYLATION OF α-SULFINYL CARBANION
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A new synthesis of α,β-unsaturated γ- and δ-lactones involving the intramolecular acylation of α-sulfinyl carbanion followed by pyrolisis is described.
- Pohmakotr, Manat,Jarupan, Prapanpong
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p. 2253 - 2256
(2007/10/02)
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- NEW SYNTHETIC REACTIONS CONTRIBUTED BY SULPHUR
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Eighteen kinds of new convenient synthetic reactions respectively contributed by divalent sulfur (7), sulfoxide (7) and sulfone (4) are shown.
- Kaji, Aritsune
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p. 211 - 222
(2007/10/02)
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- EFFICIENT TRANSFORMATION OF (Z)-2-BUTENE-1,4-DIOLS TO α,β-BUTENOLIDES: A SIMPLE SYNTHESIS OF (+/-)-ELDANOLIDE
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(Z)-2-Butene-1,4-diols are efficiently converted to the corresponding α,β-butenolides using silver carbonate/celite and this methodology has been applied to the synthesis of (+/-)-eldanolide, the wing gland pheromone of the male African sugar cane borer, Eldana saccharina (wlk).
- Chakraborty, T.K.,Chandrasekaran, S.
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p. 2891 - 2894
(2007/10/02)
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- γ-KETO ESTERS AND γ-BUTYROLACTONES FROM THE REACTION OF DIALKOXYDIHYDROFURANS WITH TRIMETHYLSILYL IODIDE
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Dimethoxydihydrofurans are converted into γ-keto esters and γ-butyrolactones by a new procedure using an equimolar quantity and an excess of trimethylsilyl iodide, respectively.
- Feringa, Ben L.,Dannenberg, W.
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p. 509 - 514
(2007/10/02)
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- SELECTIVE REACTIONS OF THIOLATE ANIONS WITH 4-HYDROXY-E-2-ALKENOIC ESTERS OR 4-METHANESULFONYLOXY-E-2-ALKENOIC ESTERS. SYNTHESIS OF 2-ALKEN-4-OLIDES (Δα,β-BUTENOLIDES) AND E,E-2,4-ALKADIENOIC ESTERS
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Methyl 4-hydroxy-E-2-alkenoates prepared from aldehydes in one step, undergo the Michael reactions with thiolate anions to give 4-alkanolide derivatives, which are converted into 2-alken-4-olides.Methyl 4-methanesulfonyloxy-E-2-alkenoates undergo the substitution reactions, and subsequent treatments give methyl E,E-2,4-alkadienoates.
- Tanikaga, Rikuhei,Nozaki, Yoshihito,Tanaka, Kazuhiko,Kaji, Aritsune
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p. 1703 - 1706
(2007/10/02)
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