- Stereoselective synthesis of pear ester
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A simple two-step synthesis of ethyl-(2E,4Z)-deca-2,4-dienoate based on Fe-catalyzed cross-coupling of ethyl-(2E,4Z)-5-chloropenta-2,4-dienoate, which was obtained via one-pot oxidation and olefination of readily available (2Z)-3-chloroprop-2-en-1-ol by n-pentylmagnesiumbromide, was developed.
- Shakhmaev,Sunagatullina, A. Sh,Akimova,Zorin
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- Preparation method of (E, Z)-2, 4-ethyl decadienoate
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The invention provides a preparation method of (E, Z)-2, 4-ethyl decadienoate. According to the preparation method, n-hexyl aldehyde is taken as an initial raw material, and three step chemical conversion is adopted to prepare a key intermediate 1-bromo heptene; 1-bromo heptene and ethyl acrylate are subjected to coupling reaction under the catalytic effect of a metal catalyst so as to obtain (E,Z)-2, 4-ethyl decadienoate. According to the preparation method, metal catalytic coupling reaction is adopted to replace a step in the prior art that (E, Z)-2, 4-ethyl decadienoate is prepared throughpreparation of an organic copper lithium reagent, water-free oxygen-free harsh conditions are avoided, operation is simplified, reaction efficiency is increased, generation of waste water and waste salt is reduced greatly, equipment investment is reduced, and the preparation method is convenient for industrialization production.
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Paragraph 0046; 0047
(2019/05/15)
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- Bisexual attractants, aggregants and arrestants for adults and larvae of codling moth and other species of lepidoptera
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Novel bisexual attractants for lepidopterous insect pests isolated from pears or apples. A method for monitoring and control of codling moth and other species of Lepidoptera comprising a lure and kill, mating disruption or mass trapping strategy. A method of using a formulation containing the bisexual attractants with or without an insecticide and/or pheromone for control of the insect pests.
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- Stereoselective synthesis of methyl and ethyl (2E,4Z)-2,4-decadienoates from (E)-4,4-dimethoxy-2-butenal
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Methyl and ethyl (2E,4Z)-2,4-decadienoates were synthesized starting from (E)-4,4-dimethoxy-2-butenal.
- Ovanesyan,Garibyan,Badanyan
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p. 951 - 954
(2007/10/03)
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- Highly cis-selective Wittig reactions employing α-heterosubstituted ylids
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1-Alkenyl chlorides, bromides or iodides can be obtained with very high cis selectivities through Wittig reaction employing α-chloro, α-bromo α-iodo ylids derive from tris(2-methoxymethoxyphenyl)phospine. The corresponding α-methoxy substituted ylid produces enethers with again remarkably high cis/trans ratios. Palladium(II) catalyzed coupling of (Z)-1-iodo-1-heptene with ethyl acrylate affords ethyl (2E,4Z)-2-4-decadienoate, the Bartlett pear fragrance, with almost quantitative yield.
- Zhang, Xin-Ping,Schlosser, Manfred
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p. 1925 - 1928
(2007/10/02)
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- A Stereoselective Synthesis of Ethyl (2E,4Z)-2,4-Decadienoate: Pear Ester
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A stereoselective synthesis of ethyl (2E,4Z)-2,4-decadienoate (1) is reported from E-pent-2-en-4-yn-1-ol in five steps.
- Sharma, G.V.M.,Rajagopal, D.
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p. 633 - 636
(2007/10/02)
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- A STEREOSELECTIVE SYNTHESIS OF PEAR ESTER VIA ARSENIC YLIDE
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The paper describes a four-step synthesis of ethyl (2E,4Z)-2,4-decadienoate (pear ester) from propargyl alcohol with a 50percent total yield.It also gives the synthesis of ethyl (2E,4E)-2,4-decadienoate.In both cases arsenic ylides were used to give the satisfactory results.
- Zhengming, Li,Tiansheng, Wang,Diankun, Zhang,Zhengheng, Gao
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- SYNTHESE STEREOSELECTIVE DU DECADIENE-2(E), 4(Z)OATE D'ETHYLE. A PARTIR D'UN MONOACETAL DU GLYOXAL
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The glyoxal monoacetal 2, now readily available in bulk quantity, is a very useful synthon for the dienes-1,3 synthesis, as illustrated in the stereoselective preparation of ethyl 2E,4Z-decadienoate using two Wittig-type olefination reactions.
- Stambouli, A.,Amouroux, R.,Chastrette, M.
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p. 5301 - 5302
(2007/10/02)
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- Conversion of 2-Sulfinylated 2-Alkenoate Esters to (2E,4E)-2,4-Alkadienoate Esters by Pyrolysis
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Thermal reaction of ethyl (2E)-2-phenylsulfinyl-2-alkenoates (E-2) prepared from aldehydes and ethyl 2-phenylsulfinylacetate have been investigated.Refluxing of E-2 or their Z-isomers in xylene resulted in the formation of ethyl (2E,4E)-2,4-alkanedioates accompanied by ethyl (2E)-4-hydroxy-2-alkenoates.Ethyl 2-cycloalkylidene-2-phenylsulfinylacetates were found to be more susceptible to pyrolysis.The enoate esters (2) undergo migration of their carbon-carbon double bond and then sigmatropic rearrangement to benzenesulfenate esters, followed by thermolytic extrusion of a benzenesulfenic acid probably via ethyl(2E)-4-phenylsulfinyl-2-alkenoates to afford ethyl (2E,4E)-2,4-alkadienoates.
- Tanikaga, Rikuhei,Nozaki, Yoshihito,Nishida, Masaharu,Kaji, Aritsune
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p. 729 - 733
(2007/10/02)
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- A Novel Stereoselective Synthesis of the "Pear Ester" Ethyl (2E,4Z)-2,4-Decadienoate
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The title compound 8 is prepared by two stereoselective Wittig olefinations.
- Bestmann, Hans Juergen,Suess, Joachim
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p. 363 - 365
(2007/10/02)
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- New Synthesis of α-Benzoyloxy Aldehydes. Application to the Stereoselective Synthesis of Conjugated (E,E)-Dienoic Esters
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A new synthetic method for the preparation of secondary α-benzoyloxy aldehydes (5a-d) and its use in the stereoselective synthesis of conjugated (E,E)-dienone (14) and dienoic esters (9b, 9c, 11, 15b, and 15c) were studied.Two-phase (benzene-H2O) reaction of RCH2CHXCHO (R=CH3, C3H7, C5H11, C7H15; X=Cl, Br) with sodium benzoate (4) in the presence of a catalytic amount of tetrabutylammonium bromide gave the corresponding α-benzoyloxy aldehydes (5a-d) in moderate yields.Compounds 5a-d were converted to γ-benzoyloxy-α,β-unsaturated carbonyl compounds or esters (7b, 7c, 10, 12, 13b, and 13c) either by the TiCl4/py-catalyzed condensation with malonate or acetoacetate or by the Wittig reaction with Ph3P=CHC(O)CH3 and Ph3P=CHCO2Et.Treatment of these compounds with 5 mol percent of (Ph3P)4Pd in refluxing THF afforded the corresponding conjugated (E,E)-dienones and dienoic esters stereoselectively.The reaction sequence was further extended to the stereoselective synthesis of ethyl (2E,4E,6E)-2,4,6-dodecatrienoate (18) and pellitorine (21).
- Sakai, Takashi,Seko, Katsuhiko,Tsuji, Akihiro,Utaka, Masanori,Takeda, Akira
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p. 1101 - 1106
(2007/10/02)
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- HIGHLY STEREOCONTOROLLED SYNTHESIS OF (2E,4Z)-DIENIC ESTERS BY ALUMINA CATALYST
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Thermal treatment of β-allenic esters (2) with alumina catalyst in aprotic solvents yielded (2E,4Z)-dienoic esters (3) in 57-87percent yields with 91-100percent stereoselectivity.
- Tsuboi, Sadao,Masuda, Toshihide,Makino, Hiroshi,Takeda, Akira
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p. 209 - 212
(2007/10/02)
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- Vinyl-copper derivatives-XI1 1 Part X: A. Alexakis, G. Cahiez and J.F. Normant, Synthesis, 826 (1979). Reactivity of Z-alkenyl cuprates towards various electrophiles. Application to the synthesis of some natural products
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Z-Alkenylcuprates 1 and 2, prepared in situ by addition of acetylene to alkylcuprates, react with a variety of electrophiles (epoxides, carbon dioxide, aldehydes) and give conjugate addition products with α,β-unsaturated aldehydes, ketones and esters, and with activated cyclopropanes. They also add across the triple bond of some alkynes. The synthesis of natural products (7,9,22) is described.
- Alexakis,Cahiez,Normant
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p. 1961 - 1969
(2007/10/02)
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