- Reactivity of 3-Nitro-5,6-Dihydro-4H-Pyran with Organoalanes: Preparation of (E)-α, β-Ethylenic Aldehydes
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3-Nitro-5,6-dihydro-4H-pyran reacts with organoalanes and gives 1,4 addition products.In suitable hydrolysis conditions, the reaction results in the formation of aldehydes that are C1-homologues of the chain transferred by the alane.
- Menicagli, Rita,Guagnano, Vito,Malanga, Corrado
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Read Online
- A new stereoselective synthesis of trans-α, β- unsaturated carbonyl compounds.
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Allenic silylated ethers are efficient precursors to unsaturated carbonyl compounds.
- Clinet, Jean-Claude,Linstrumelle, Gerard
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Read Online
- Alkene-Zipper Catalyzed Selective and Remote Retro-ene Reaction of Alkenyl Cyclopropylcarbinol
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Reminiscent of biological systems, the increasingly popular concept of remote activation allows a greater strategic synthetic flexibility for the development of novel synthetic organic methodologies. In this Communication, we report that commercially available ruthenium (II)-based “alkene zipper catalyst” enables the selective transformation of a large variety of ω-alkenyl cyclopropylcarbinols into stereodefined unconjugated (E)-acyclic aldehydes bearing a quaternary stereocenter through an isomerization followed by a retro-ene reaction. To unravel this peculiar catalytic property of the “alkene zipper” and shed some light on the mechanism, a series of control experiments were performed. (Figure presented.).
- Bruffaerts, Jeffrey,Vasseur, Alexandre,Marek, Ilan
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Read Online
- An efficient Pd@Pro-GO heterogeneous catalyst for the α, β-dehydrogenation of saturated aldehyde and ketones
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An Efficient Pd@Pro-GO heterogeneous catalyst was developed that can promote the α, β-dehydrogenation of saturated aldehyde and ketones in the yield of 73% ? 92% at mild conditions without extra oxidants and additives. Pd@Pro-GO heterogeneous catalyst was synthesized via two steps: firstly, the Pro-GO was obtained by the esterification reaction between graphene oxide (GO) and N-(tert-Butoxycarbonyl)-L-proline (Boc-Pro-OH), followed by removing the protection group tert-Butoxycarbonyl (Boc), which endowed the proline-functionalized GO with both the lewis acid site (COOH) and the bronsted base site (NH), besides, the pyrrolidine of proline also can form imine with aldehydes to activate these substrates; Second, palladium was dispersed on the proline-functionalized GO (Pro-GO) to obtained heterogeneous catalyst Pd@Pro-GO. Mechanistic studies have shown that the Pd@Pro-GO-catalyzed α,β-dehydrogenation of saturated aldehyde and ketones was realized by an improved heterogeneously catalyzed Saegusa oxidation reaction. Based on the obove characteristics, the Pd@Pro-GO will be widely used in the transition metal catalytic field.
- Pan, Gao-Fei,Wang, Zhe,Chang, Yi-Yuan,Hao, Yue,Wang, Yi-Chen,Xing, Rui-Guang
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supporting information
(2021/12/30)
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- Synthesis of (5Z,7E)-dodecane-5,7-diene-1-alcohol as well as acetate and propionate thereof
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The invention belongs to the technical field of insect pheromone synthesis, and discloses a new method for synthesizing (5Z,7E)-dodecane-5,7-diene-1-alcohol as well as acetate and propionate thereof.The method takes propynol as an initial raw material to be subjected to coupling with 1-bromobutane to generate 2-heptyne-1-alcohol, triple bond is reduced to be E-type double bond through LiAlH4, 2-heptyne-1-alcohol is oxidized to be olefine aldehyde through PDC, olefine aldehyde reacts with a Wittig reagent (5-ethyoxyl-5-oxopentyl)triphenyl phosphonium bromide to produce (5Z,7E)-dodecane-5,7-dienoic acid ethyl ester which is reduced by LiAlH4 to obtain (5Z,7E)-dodecane-5,7-diene-1-alcohol, (5Z,7E)-dodecane-5,7-diene-1-alcohol reacts with acetyl chloride and propionyl chloride finally to obtain (5Z,7E)-dodecane-5,7-diene-1-alcohol acetate and (5Z,7E)-dodecane-5,7-diene-1-alcohol propionate. The method utilizes LiAlH4 to reduce the triple bond to be the E-type double bond, and utilizes theWittig reaction of the Wittig reagent with the tail end provided with ester group and aldehyde to directly build the Z-type double bond, the synthesis route is simple, convenient and efficient, and the reaction condition is moderate and environmentally friendly.
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Paragraph 0032-0034
(2019/03/28)
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- Fe3O4 Nanoparticles Anchored on Carbon Serve the Dual Role of Catalyst and Magnetically Recoverable Entity in the Aerobic Oxidation of Alcohols
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A composite of Fe3O4 nanoparticles anchored on a carbon support (Fe3O4/C), possessing both superparamagnetism and molecular oxygen activating properties, was prepared by an ammonia-assisted precipitation method. Fe3O4/C could catalyze the selective oxidation of various benzyl alcohols with air as the oxidant source, and could be easily separated and recycled with an external magnet. The small particle size and the interaction between the Fe3O4 nanoparticles and carbon support endow the Fe3O4/C catalyst with relatively high reducibility. Its oxidation state is easy to change. This intrinsic property of the Fe3O4 nanoparticles could be responsible for the high activity of Fe3O4/C in the aerobic oxidation of alcohols.
- Geng, Longlong,Zheng, Bin,Wang, Xiang,Zhang, Wenxiang,Wu, Shujie,Jia, Mingjun,Yan, Wenfu,Liu, Gang
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p. 805 - 811
(2016/03/05)
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- Highly enantioselective copper(i)-catalyzed conjugate addition of 1,3-diynes to α,β-unsaturated trifluoromethyl ketones
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The conjugate diynylation of α,β-unsaturated trifluoromethyl ketones is carried out in the presence of a low catalytic load (2.5 mol%) of a copper(i)-MeOBIPHEP complex, triethylamine and a terminal 1,3-diyne. Pre-metalation of the terminal 1,3-diyne with stoichiometric or higher amounts of dialkylzinc reagent is not required. The corresponding internal diynes bearing a propargylic stereogenic center are obtained with good yields and excellent enantioselectivities. This journal is
- Sanz-Marco, Amparo,Blay, Gonzalo,Mu?oz, M. Carmen,Pedro, José R.
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supporting information
p. 8958 - 8961
(2015/05/27)
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- Synthesis of α,β-unsaturated aldehydes and nitriles via cross-metathesis reactions using Grubbs' catalysts
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A series of α,β-unsaturated aldehydes and nitriles of significant interest in the fragrance industry have been prepared using Grubbs' catalysts in cross-metathesis reactions of electron-deficient olefins (i.e., acrolein, crotonaldehyde, methacrolein, and acrylonitrile) with various 1-alkenes, including 1-decene, 1-octene, 1-hexene and 2-allyloxy-6-methylheptane. The latter is of particular interest, as it has not previously being used as a substrate in cross-metathesis reactions and allows access to valuable intermediates for the synthesis of new fragrances. Most reactions gave good selectivity of the desired CM product (≥90%). Detailed optimisation and mechanistic studies have been performed on the cross-metathesis of acrolein with 1-decene. Recycling of the catalyst has been attempted using ionic liquids.
- Rountree, Sandra M.,Taylor, Sarah F.R.,Hardacre, Christopher,Lagunas, M. Cristina,Davey, Paul N.
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- Iron-catalyzed aerobic oxidation of allylic alcohols: The issue of C=C bond isomerization
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An aerobic oxidation of allylic alcohols using Fe(NO3) 3·9H2O/TEMPO/NaCl as catalysts under atmospheric pressure of oxygen at room temperature was developed. This eco-friendly and mild protocol provides a convenient pathway to the synthesis of stereodefined α,β-unsaturated enals or enones with the retention of the C-C double-bond configuration.
- Liu, Jinxian,Ma, Shengming
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supporting information
p. 5150 - 5153
(2013/11/06)
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- Evaluation of the formation and stability of hydroxyalkylsulfonic acids in wines
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The presence of carbonyl compounds (CCs) in wines has sparked the interest of researchers in several countries. The quantification of some of these compounds has been used as a parameter of quality for many fermented beverages. Although present in minute quantities (except for acetaldehyde), they have a strong olfactory impact. In addition, the CCs found in wines have a strong affinity for bisulfite and can form stable adducts, which will also interfere in the characteristics of aroma. The greatest challenge, however, is to predict which CCs have the strongest affinity for S(IV) and what conditions favor this interaction. To better understand the reaction of CC-bisulfite adduct formation (HASA), this study has evaluated the profile of 22 CCs in a "synthetic wine" containing bisulfite and in 10 real samples of different wines from the Sao Francisco Valley, northeastern Brazil. On the basis of principal component analysis (PCA) and dissociation constants, the results revealed that aliphatic aldehydes form adducts with S(IV), whereas ketones, cyclic aldehydes, and trans-alkenes interact weakly and are found predominantly in their free form. These results revealed also that pH 10 and 11 were defined as the most appropriate for CC-SO2 adduct dissociation, and the total CCs were quantified reliably.
- De Azevedo, Luciana C.,Reis, Marina M.,Motta, Luiz F.,Da Rocha, Gisele O.,Silva, Luciana A.,De Andrade, Jailson B.
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scheme or table
p. 8670 - 8680
(2009/09/28)
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- Direct preparation of copper organometallics bearing an aldehyde function via an iodine-copper exchange
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The iodine-copper exchange reaction allows the direct preparation of various aryl, heteroaryl and alkenyl cuprates bearing a formyl group, thus allowing a direct synthesis of polyfunctional aldehydes without the need of protecting groups or an additional oxidation step. The Royal Society of Chemistry 2006.
- Yang, Xiaoyin,Knochel, Paul
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p. 2486 - 2488
(2008/03/28)
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- Catalytic Conversions in Water. Part 23: Steric Effects and Increased Substrate Scope in the Palladium-Neocuproine Catalyzed Aerobic Oxidation of Alcohols in Aqueous Solvents
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The steric influence of substituents on the 2-and 9-positions of phenanthroline in the (2,9-R2-1,10-phenanthroline)palladium(II)- catalyzed aerobic oxidation of 2-hexanol was investigated by means of high throughput experimentation. (Neocuproine)Pd-(OAc)2 (R=CH 3) was found to be a highly active catalyst for alcohol oxidation in 1:1 water/DMSO mixtures. The catalyst is unique in that it tolerates water, polar co-solvents and a wide variety of functional groups in the alcohol. Turn-over frequencies of > 1500 h-1 were achieved and a series of alcohols was oxidised with 0.1 to 0.5 mol % of catalyst.
- Ten Brink, Gerd-Jan,Arends, Isabel W. C. E.,Hoogenraad, Marcel,Verspui, Goeran,Sheldon, Roger A.
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p. 1341 - 1352
(2007/10/03)
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- A convenient route to α,β-unsaturated aldehydes based on polymer-supported α-selenoaldehydes
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Polystyrene-supported (4-phenylseleno)morpholine was synthesised and could be used as an efficient α-selenenylating agent for saturated aldehydes; subsequent oxidation of polystyrene-supported α-selenoaldehydes and the products from the Wittig reaction of them with chloromethylidenetriphenylphosphorane with an excess of 30% hydrogen peroxide at room temperature afforded α,β-unsaturated aldehydes in good yields and purities.
- Sheng, Shou-Ri,Wu, Lu-Ling,Huang, Xian
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p. 258 - 259
(2007/10/03)
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- Bis(o-nitrophenyl)ethanediol: A practical photolabile protecting group for ketones and aldehydes
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The ketals of bis(o-nitrophenyl)ethanediol and ketones or aldehydes are smoothly deprotected in neutral conditions by irradiation with 350 nm light. The chemical stability in basic, acidic, and oxidizing media makes this form of protection orthogonal to classical protecting groups. Both racemic and enantiopure forms are readily available in two steps from inexpensive starting materials.
- Blanc, Aurelien,Bochet, Christian G.
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p. 1138 - 1141
(2007/10/03)
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- Epoxidation of allylic alcohols in aqueous solutions of non surfactant amphiphilic sugars
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A variety of cyclic and acyclic allylic alcohols undergo efficient chemo-, regio- and/or stereoselective epoxidations in neutral aqueous solutions of amphiphilic carbohydrates (sucrose, L-arabinose, methyl or ethyl β-D-fructopyranoside) by using dilute hydrogen peroxide in the presence of molybdic or tungstic salts.
- Denis,Misbahi,Kerbal,Ferrieres,Plusquellec
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p. 2460 - 2461
(2007/10/03)
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- Acetylenic silyl ketone as polysynthetic equivalent of useful building blocks in organic synthesis
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Ethynyl silyl ketone 1 proved to be a very efficient Michael acceptor in carbocupration and metallocupration reactions. In particular, when using carbocuprates, a smooth entry to polyenals can be obtained, while, when using metallocuprates, silyl- and stannylpropenoyl silanes may be obtained, very powerful intermediates in organic synthesis.
- Capperucci, Antonella,Degl'Innocenti, Alessandro,Dondoli, Paolo,Nocentini, Tiziano,Reginato, Gianna,Ricci, Alfredo
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p. 6267 - 6276
(2007/10/03)
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- Carbonyl transposition on organoselenium compounds
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Carbonyl conjugated vinylic selenides undergo 1,3 and 1,5-carbonyl transposition sequences through organometallic reagents addition reactions followed by acid hydrolysis.
- Comasseto, Joao V.,Lo, Wai L.,Petragnani, Nicola
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p. 7445 - 7460
(2007/10/03)
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- Highly General Synthesis of - and -3-Alkylsubstituted Allyboronates via One-Carbon Homologation of Stereospecific 1-Alken-1-ylboronates
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Stereospecific 1-alkan-1-ylboronates readily react with in situ generated chloromethyllithium, producing the corresponding allylboronate in good yields and in excellent stereochemical purities.These are very important synthetic intermediates and conversion of a representative derivative, -2-(2-heptenyl)-1,3,2-dioxaborinane, 2 (R1=C4H9, R2=R3=H), into several compounds of synthetic interest is described.
- Brown, Herbert C.,Phadke, Avinash S.,Bhat, Narayan G.
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p. 7845 - 7848
(2007/10/02)
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- 3-Nitro-5,6-dihydro-4H-pyran, a Latent -CHO Equivalent: A New Synthesis of Aldehydes
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3-Nitro-5,6-dihydro-4H-pyran reacts with organoaluminum compounds and, after hydrolysis with 3 N HCl, gives aldehydes arising from a formal carbonylation of the alane.
- Menicagli, R.,Malanga, C.,Guagnano, V.
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p. 2867 - 2870
(2007/10/02)
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- β-Phenylseleno α,β-unsaturated aldehydes, efficient three carbon homologating agents. 1,3-carbonyl transposition
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The easily obtained β-phenylseleno α,β-unsaturated aldehydes react with Grignard reagents and with n-butyllithium leading to the 1,2-addition products, which upon acidic hydrolysis in the presence of silica gel afford the selenium-free α,β-unsaturated carbonyl compounds with 1,3-carbonyl transposition.
- Arrua,Comasseto
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p. 1663 - 1666
(2007/10/02)
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- Oxidation of Alcohols with Electrolytic Manganese Dioxide. Its Application for the Synthesis of Insect Pheromones
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Oxidation of alcohols with electrolytic manganese dioxide under mild conditions afforded aldehydes and ketones in good yields.The method was applied for the syntheses of cystophorene (15) and a sex pheromone of forest tent cater pillar .
- Tsuboi, Sadao,Ishii, Naomi,Sakai, Takashi,Tari, Isao,Utaka, Masanori
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p. 1888 - 1893
(2007/10/02)
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- A Simple Route to α,β-Unsaturated Aldehydes from Prop-2-ynols
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2-Ynols can be isomerised stereoselectively to (2E)-enals with a ruthenium complex as catalyst.
- Ma, Dawei,Lu, Xiyan
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p. 890 - 891
(2007/10/02)
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- Methods for the introduction of a Phenylselenium Dichloride Group into he α-position of Carbonyl Compounds. Syntheses of Enones.
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Phenylselenium trichloride, PhSeCl3, direcly introduced, in fair yield, a PhSeCl2 group into the α-position of ketones with loss of HCl.To some extent, depending on the substrate, this reagent was also shown to act as a chlorinating agent toward ketones, yielding α-chloro ketones and α-phenylselenenyl ketones.The latter compounds were readily converted to selenium(IV) dichlorides by SO2Cl2 chlorination to significantly improve the overall yields of the selenetion process.The consecutive treatment of ketones with PhSeCl and SO2Cl2 could also be used for the introduction of a PhSeCl2 group, but this procedure was usually less efficient than the PhSeCl3-based one.Unsymmetrical ketones were selenated with poor regiocontrol.Aldehydes were primarily chlorinated by treatment with PhSeCl3, but consecutive treatment with PhSeCl3 and SO2Cl2 introduced a PhSeCl2 group into the α-position.Carboxylic acids and esters were ureactive toward PhSeCl3 and PhSeCl.PhSeCl3 underwent addition reactions with enones to introduce a PhSeCl2 group α or β to the carbonyl group, depending on the substrate.The carbonyl compounds substituted in the α-position with a PhSeCl2 group were easily converted to the corresponding α,β-unsaturated carbonyl compounds after hydrolysis/selenoxide elimination.Since the selenium(IV) intermediates involved were highly crustalline and easy to purify, the preparation of enones from symmetrical ketones via PhSeCl2 introduction/hydrolytic elimination was especially convenient to perform from the operational point of view.
- Engman Lars
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p. 4031 - 4037
(2007/10/02)
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- THIOSTANNANE-MEDIATED PREPARATION OF γ-ALKOXYALLYL SULFIDES; EFFICIENT β-ALKYLATION OF α,β-UNSATURATED ALDEHYDES
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The title β-alkylation is achieved through a sequence of sulfenylation of α-enal acetals, t-BuLi-promoted alkylation, and oxidative hydrolysis.
- Sato, Tsuneo,Okazaki, Hiroshi,Otera, Junzo,Nozaki, Hitosi
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p. 2979 - 2982
(2007/10/02)
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- ALIPHATIC THIOETHERS
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Novel asymmetric thioethers of the formula STR1 in which R. sup.1 represents a C 1-3-alkyl radical or a C 1-3-hydroxyalkyl radical of which the hydroxy group may be in esterified form,R. sup.2 represents an optionally unsaturated aliphatic radical having from 5 to 15 carbon atoms,R 3 represents hydroxy, alkoxy or an optionally substituted amino group, and-X-represents a single bond, a methylene group or an optionally N-acylated primary aminomethylene groupwherein the O-atom of the hydroxy group is in the transconfiguration relative to the S-atom, are effective as leucotriene-antagonists since they eliminate the contractions of smooth muscles caused by leucotrienes and are therefore suitable for the treatment of allergic, especially asthmatic, conditions.
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- Syntheses d'alcools allyliques et alleniques fonctionnels a partir de composes carbonyles α-phenylselenies
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The functionalized allylic selenides 6, 7, 8, 10 and 11 were prepared from phenylselenoaldehydes and ketones 1, and phenylselenopyruvates 2 using the Wittig or the Horner reaction. 2,3-Sigmatropic rearrangement of the corresponding selenoxides leads to the functional allylic alcohols 15, 16 and 17 and to the conjugated enals 18, 19 and 20.A method for the conversion of an aldehyde into the enal with an additional carbon is described.The functional 3-phenylselenobutadienes 23, 24 and 25 were also obtained from α-phenylselenoenals 21 in the same manner.An oxidation-rearrangement reaction appears to be a convenient way to prepare the functional or substitued allenic alcohols 26 and 28.The ethyl 2-hydroxy pent-3,4-dienoate 26c has been cyclized by benzeneselenenyl bromide into the ethyl 2,5-dihydrofurancarboxylate 29.
- Lerouge, Patrice,Paulmier, Claude
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p. 1225 - 1229
(2007/10/02)
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- Pyridylseleno Group in Organic Synthesis. Preparation and Oxidation of α-(2-Pyridylseleno) Carbonyl Compounds Leading to α,β-Unsaturated Ketones and Aldehydes
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α-(2-Pyridylseleno) carbonyl compounds (A) were prepared by the reaction of ketones or aldehydes with 2-pyridylselenenyl bromide under various conditions (acidic, basic, or after conversion to silyl enol ethers) in good to excellent yields.Oxidation of A thus prepared affords α,β-unsaturated carbonyl compounds in excellent yields even in the cases where satisfactory results were not obtained by the oxidation of the corresponding α-phenylseleno carbonyl compounds.These results indicate that the 2-pyridylseleno group is a better leaving group than the phenylseleno group in selenoxide elimination leading to enones.
- Toshimitsu, Akio,Owada, Hiroto,Terao, Keiji,Uemura, Sakae,Okano, Masaya
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p. 3796 - 3800
(2007/10/02)
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- ALKENYL COPPER REAGENTS-18; CARBOCUPRATION OF ACETYLENIC ACETALS AND KETALS; SYNTHESIS OF MANICONE, GERANIAL AND 2,4(E,Z)-DIENALS
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Lithium diorganocuprates add across the triple bond of substituted and non-substituted acetylenyl acetals and ketals to give dialkenylcuprates, which can be decomposed into alkoxyallenes or may be trapped with a variety of electrophiles, such as alkyl, alkenyl, alkynyl and aryl halides.They may also undergo conjugate addition to α-β unsaturated esters and ketons.The method is used for the synthesis of (+/-)-manicone, pure geranial and (E,Z)2,4-dienals.
- Alexakis, A.,Commercon, A,Coulentianos, C.,Normant, J.F.
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p. 715 - 732
(2007/10/02)
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- PROPRIETES DES α-PHENYLSELENOALDEHYDES REACTIONS DE WITTIG CONDUISANT A DES α-HYDROXYESTERS ET CETONES β,γ-ETHYLENIQUES ET A DES ALDEHYDES α,β-ETHYLENIQUES
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Wittig and Wittig-Horner reactions with α-phenylselenoaldehydes lead to allylic selenides.The corresponding selenoxides undergo 2,3-sigmatropic rearrangement providing a route to α-hydroxy β,γ-ethylenic esters and ketones in good yields.In a some way, we prepare, also enals with an additional carbon.
- Lerouge, Patrice,Paulmier, Claude
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p. 1983 - 1986
(2007/10/02)
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- REACTIVITY OF THE 1-t.BUTYLTHIO-3-METHOXY-1-ALKENES TOWARDS METALATING AGENTS, II. ALLYLIC DEPROTONATION OF THE E-ISOMERS AND OF THE Z-PROPENYL DERIVATIVE.
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Deprotonation of the title compounds with a lithiating agent and subsequent alkylation furnish the 1-substituted products 4.The 1-t.butylthio-3-methoxy-1-lithio-1-alkenes 3 become new equivalents of the hypothetical anions I.
- Ruel, O.,Ekogha, C. Bibang Bi,Julia, S. A.
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p. 4829 - 4832
(2007/10/02)
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- ALKOXY-3 ACROLEINES: EQUIVALENTS DU DIALDEHYDE MALONIQUE
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Preparation and some synthetic applications of alkoxy-3 acroleines 1, useful three carbons unit synthons, equivalent of malondialdehyde, are described.
- Maddaluno, Jacques,d'Angelo, Jean
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p. 895 - 898
(2007/10/02)
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- THE TETRAHYDROPYRANYL ETHER OF (E)-3-BROMO-3-TRIMETHYLSILYL-2-PROPEN-1-OL, A SINGLE SYNTHON FOR THE (E)-β-FORMYLVINYL ANION AND CATION
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The tetrahydropyranyl ether of (E)-3-bromo-3-trimethylsilyl-2-propen-1-ol can serve as a single synthon for both the (E)-β-formylvinyl anion and cation depending upon the manner in which the bromine group is stereospecifically replaced by an alkyl group.
- Miller, R. Bryan,Al-Hassan, Mohamed I.
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p. 2055 - 2058
(2007/10/02)
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- Synthesis of α,β-Unsaturated Carbonyl Compounds by Successive Rearrangement and Peterson Olefination of β'-Hydroxy-α,β-epoxysilanes
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The reaction of β'-hydroxy-α,β-epoxysilanes with boron trifluoride-diethyl ether results in rearrangement of the epoxysilane skeleton followed by Peterson olefination, leading to α,β-unsaturated carbonyl compounds.
- Sato, Fumie,Tanaka, Youichi,Kanbara, Hiroshi
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p. 1024 - 1025
(2007/10/02)
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- Cumulated Ylides, XII. A Stereoselective Synthetic Method for (Z)-α,β-Unsaturated Aldehydes
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(2-Ethoxyvinyl)triphenylphosphonium bromide (5) is converted with sodium amide into the corresponding phosphaallenylide 6 which adds ethanol forming the ylide 7. 7 is also obtained by the reaction of 5 with sodium ethanolate.The Wittig reaction of 7 with aldehydes 2 proceeds with high (Z)-stereoselectivity to give (Z)-α,β-unsaturated acetals 8 which are cleaved under well defined conditions with p-toluenesulfonic acid or with wet silica gel to (Z)-α,β-unsaturated aldehydes 9.
- Bestmann, Hans Juergen,Roth, Kurt,Ettlinger, Manfred
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p. 161 - 171
(2007/10/02)
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- ENONE SYNTHESIS VIA α-PYRIDYLSELENO CARBONYL COMPOUNDS
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Oxidative elimination of α-pyridylseleno carbonyl compounds affords enones in excellent yields, providing an improved method for dehydrogenation of ketones and aldehydes.These results indicate that pyridylseleno group is a better leaving group than phenylseleno group in selenoxide elimination leading to enones.
- Toshimitsu, Akio,Owada, Hiroto,Uemura, Sakae,Okano, Masaya
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p. 2105 - 2108
(2007/10/02)
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- SYNTHESIS OF α,β-UNSATURATED ALDEHYDES VIA 1-AMINOPROPA-1,2-DIENES: MECHANISTIC STUDIES
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A facile prototropic rearrangement of N-(prop-2-ynyl)amines to 1-aminopropa-1,2-dienes, followed by acid hydrolysis, affords a novel synthesis of α,β-unsaturated aldehydes.The mechanism of the reaction has been examined by deuterium labeling.
- Craig, J. Cymerman,Ekwuribe, Nnochiri N.
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p. 2587 - 2590
(2007/10/02)
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- REINVESTIGATION OF THE GRIGNARD REACTIONS WITH FORMIC ACID. A CONVENIENT METHOD FOR PREPARATION OF ALDEHYDES
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Grignard reagents react with formic acid in tetrahydrofuran to produce aldehydes in relatively good yields.Various aldehydes such as alkyl, aryl, allyl, benzyl and vinyl aldehydes were prepared from the corresponding Grignard reagents.The reaction with vinyl Grignard reagents proceeded with retention of configuration.
- Sato, Fumie,Oguro, Kaoru,Watanabe, Hiroshi,Sato, Masao
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p. 2869 - 2872
(2007/10/02)
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- An approach to the synthesis of C18 tri-insaturated fatty acids.
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New approaches for the synthesis of cis, trans, trans, octadeca-9,11,13-trienoic acid (I) and its trans, trans, cis isomer (II), starting from the easily available propargyl alcohol are described.
- Petragnani,Brocksom,Gato
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p. 627 - 634
(2007/10/12)
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