- Isolation and Structure of Pseurotin A, a Microbial Metabolite of Pseudeurotium ovalis Stolk with an Unusual Heterospirocyclic System
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The structure and absolute configuration of pseurotin A, a new metabolite, isolated from culture filtrates of Pseudeurotium ovalis Stolk (Ascomycetes) has been shown to be (1'S,2'S,5S,8S,9R,3'Z)-8-benzoyl-2(1',2-dihydroxy-3'-hexenyl)-9-hydroxy-8-methoxy-1-oxa-7-azaspironon-2-ene-4,6-dione (1).
- Bloch, Peter,Tamm, Christoph
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Read Online
- Chromium-Catalyzed Production of Diols From Olefins
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Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
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Paragraph 0111
(2021/03/19)
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- C-GLUCOSIDE DERIVATIVE CONTAINING FUSED PHENYL RING OR PHARMACEUTICALLY ACCEPTABLE SALT THEREOF, PROCESS FOR PREPARING SAME, AND PHARMACEUTICAL COMPOSITION COMPRISING SAME
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The present disclosure relates to C-glycoside derivatives having a fused phenyl ring or pharmaceutical acceptable salts thereof, a method for preparing the same, a pharmaceutical composition comprising the same, a use thereof and a method for dual inhibition of SGLT1 and SGLT2 using the same. A novel compound of the present disclosure has a dual inhibitory activity against SGLT1 and SGLT2, thus being valuably used as a diabetes therapeutic agent.
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Paragraph 0359-0360
(2018/12/04)
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- Catalytic Reactions of Homo- and Cross-Condensation of Ethanal and Propanal
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Abstract: Processes of catalytic homocondensation of propanal and its cross-condensation with ethanal and methanal in the presence of aniline and amino acids have been studied. The dependence of the conversion of the reactants and selectivity of the homo/heterocondensation process on the catalyst nature and temperature has been revealed. It has been shown that the maximum acrolein selectivity is reached in the case of using benzoyl-substituted derivatives in water, with the proportion of the products of further condensation decreasing. The selectivity for the ethanal homocondensation product 2-butenal decreases simultaneously as a result of the formation of linear and branched oligomers of successive condensation.
- Martsinkevich,Bruk,Dashko,Afaunov,Flid,Sedov
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p. 1032 - 1035
(2019/01/03)
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- Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst
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Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.
- Zhang, Mengqi,Zhai, Yongyan,Ru, Shi,Zang, Dejin,Han, Sheng,Yu, Han,Wei, Yongge
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supporting information
p. 10164 - 10167
(2018/09/13)
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- Highly Enantioselective Synthesis of Alkylpyridine Derivatives through a Michael/Michael/Aldol Cascade Reaction
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A method for the synthesis of pyridine derivatives based on a triple cascade reaction catalyzed by chiral secondary amines was developed. The resulting cyclohexenes (three C–C bonds were formed) were obtained in good yields with good diastereoselectivities and excellent enantioselectivities.
- Meazza, Marta,Potter, Michael,Pitak, Mateusz B.,Coles, Simon J.,Mazzanti, Andrea,Rios, Ramon
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supporting information
p. 719 - 725
(2017/02/05)
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- Evidence for isomerizing hydroformylation of butadiene. A combined experimental and computational study
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The (DIOP)rhodium-catalyzed hydroformylation of butadiene has been shown to give among the highest selectivities for formation of adipaldehyde, which is useful for the synthesis of nylon. Herein, isomerizing hydroformylation is shown to be a mechanism that is partially responsible for this selectivity and density functional theory studies are used to reveal the detailed pathway for the requisite alkene isomerization.
- Maji, Tapan,Mendis, Camina H.,Thompson, Ward H.,Tunge, Jon A.
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p. 145 - 152
(2016/09/09)
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- Lipid-derived aldehyde degradation under thermal conditions
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Nucleophilic degradation produced by reactive carbonyls plays a major role in food quality and safety. Nevertheless, these reactions are complex because reactive carbonyls are usually involved in various competitive reactions. This study describes the thermal degradation of 2-alkenals (2-pentenal and 2-octenal) and 2,4-alkadienals (2,4-heptadienal and 2,4-decadienal) in an attempt to both clarify the stability of aldehydes and determine new compounds that might also play a role in nucleophile/aldehyde reactions. The obtained results showed that alkenals and alkadienals decomposed rapidly in the presence of buffer and air to produce formaldehyde, acetaldehyde, and the aldehydes corresponding to the breakage of the carboncarbon double bonds: propanal, hexanal, 2-pentenal, 2-octenal, glyoxal, and fumaraldehyde. The activation energy of double bond breakage was relatively low (~25 kJ/mol) and the yield of alkanals (10-18%) was higher than that of 2-alkenals (~1%). All these results indicate that these reactions should be considered in order to fully understand the range of nucleophile/aldehyde adducts produced.
- Zamora, Rosario,Navarro, José L.,Aguilar, Isabel,Hidalgo, Francisco J.
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- Thiol-functionalized fructose-derived nanoporous carbon as a support for gold nanoparticles and its application for aerobic oxidation of alcohols in water
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Gold nanoparticles supported on thiol-functionalized fructose-derived nanoporous carbon (AuNPs@thiol-Fru-d-NPS) were found to be a simple bench-top, biocompatible, recyclable and selective catalytic system for the aerobic oxidation of various types of alcohols into their corresponding aldehydes and ketones at room temperature under the environmentally friendly conditions with excellent yields. Copyright
- Mahyari, Mojtaba,Shaabani, Ahmad,Behbahani, Mohammad,Bagheri, Akbar
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p. 576 - 583
(2014/08/05)
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- Biooxidation of Primary Alcohols to Aldehydes through Hydrogen Transfer Employing Janibacter terrae
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Chemoselective oxidations still represent a challenge for chemists. Lyophilized cells of Janibacter terrae were employed for the chemoselective oxidation of primary alcohols to the corresponding aldehydes by hydrogen transfer with the use of acetaldehyde as the hydrogen acceptor. Secondary alcohol moieties were transformed at a much slower rate. The substrate spectrum encompasses substituted benzyl alcohols, whereby substrates with a substituent in the meta position were well tolerated, whereas only very small substituants were tolerated in the ortho position. Furthermore, nalkanols and allylic alcohols were transformed with good conversions. The biocatalyst was compatible with DMSO as a water miscible organic solvent up to 30 % v/v.
- Orbegozo, Thomas,De Vries, Johannes G.,Kroutil, Wolfgang
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experimental part
p. 3445 - 3448
(2010/09/05)
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- Catalytic aerobic oxidation of allylic alcohols to carbonyl compounds under mild conditions
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A new catalytic aerobic oxidation of alcohols to aldehydes under green conditions was developed (room temperature and pressure, water solution, open vials). The water-soluble platinum(II) tetrasulfophthalocyanine (PtPcS) catalyst showed the best selectivity for carbonyl derivatives, and in particular for α,β-unsaturated alcohols; the reactions are slow.
- Tonucci, Lucia,Nicastro, Marco,D'Alessandro, Nicola,Bressan, Mario,D'Ambrosio, Primiano,Morvillo, Antonino
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experimental part
p. 816 - 820
(2010/04/23)
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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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- The atmospheric photolysis of E-2-hexenal, Z-3-hexenal and E,E-2,4-hexadienal
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The atmospheric photolysis of E-2-hexenal, Z-3-hexenal and E,E-2,4-hexadienal has been investigated at the large outdoor European Photoreactor (EUPHORE) in Valencia, Spain. E-2-Hexenal and E,E-2,4-hexadienal were found to undergo rapid isomerization to produce Z-2-hexenal and a ketene-type compound (probably E-hexa-1,3-dien-1-one), respectively. Both isomerization processes were reversible with formation of the reactant slightly favoured. Values of j(E-2-hexenal)/j(NO2) = (1.80 ± 0.18) × 10-2 and j(E,E-2,4-hexadienal)/j(NO2) = (2.60 ± 0.26) × 10-2 were determined. The gas phase UV absorption cross-sections of E-2-hexenal and E,E-2,4-hexadienal were measured and used to derive effective quantum yields for photoisomerization of 0.36 ± 0.04 for E-2-hexenal and 0.23 ± 0.03 for E,E-2,4-hexadienal. Although photolysis appears to be an important atmospheric degradation pathway for E-2-hexenal and E,E-2,4-hexadienal, the reversible nature of the photolytic process means that gas phase reactions with OH and NO3 radicals are ultimately responsible for the atmospheric removal of these compounds. Atmospheric photolysis of Z-3-hexenal produced CO, with a molar yield of 0.34 ± 0.03, and 2-pentenal via a Norrish type I process. A value of j(Z-3-hexenal)/j(NO2) = (0.4 ± 0.04) × 10-2 was determined. The results suggest that photolysis is likely to be a minor atmospheric removal process for Z-3-hexenal. the Owner Societies.
- O'Connor, Margaret P.,Wenger, John C.,Mellouki, Abdelwahid,Wirtz, Klaus,Munoz, Amalia
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p. 5236 - 5246
(2008/02/12)
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- Protective groups for crossed aldol condensations
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A process for protecting aldehydes and ketones in crossed aldol condensations where both aldols possess alpha-carbon hydrogens, comprising protecting the target aldol by forming an acetal or imine with an alcohol, glycol or primary amine which may contain electron-withdrawing groups, adding a base of sufficient strength to abstract a proton from the alpha-carbon of the acetal or imine and adding the second aldol to form the salt of the saturated hydroxy addition compound, thereby minimizing by-products, waste and separation difficulties, then forming the unsaturated addition compound and decomposing the acetal or imine with dilute acid. This process having the advantage that a ketone may be added to a protected aldehyde target to produce an aldehyde as a product which was not previously possible.
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Page/Page column 1-2
(2008/06/13)
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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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- Efficient transformation of propargylic alcohols to α,β-unsaturated aldehydes catalyzed by ruthenium/water under neutral conditions
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α,β-Unsaturated aldehydes were selectively obtained in high yields from propargylic alcohols in aqueous solutions using RuCpCl(PR3)2 (Cp=η5-C5H5) as a catalyst. Of the tert-phosphine ligands examined, PMe3 gave the most satisfactory results. Typically, RuCpCl(PMe3)2 (5 mol%) catalyzed the transformation of oct-1-yn-3-ol at 100°C to give 2-octenal in an isolated yield of 85% (E/Z=80/20).
- Suzuki, Toshiaki,Tokunaga, Makoto,Wakatsuki, Yasuo
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p. 7531 - 7533
(2007/10/03)
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- Synthesis of oxygen-containing compounds from 1,4-pentadiene
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1,4-Pentadiene oxidation with pinane and cumene hydroperoxides was examined. The application of crude cumene hydroperoxide was shown to yield 90% 1,2-epoxypentene-4 at an oxidant conversion of over 95%. The isomerization of 1,2-epoxypentene-4 in the vapor phase at 290-330°C on lithium phosphate was studied. The rearrangement yielded 2,4-pentadiene-1-ol and unsaturated carbonyl compounds in a nearly 1:1 ratio at an epoxide conversion of 50%. Carbonyl compounds consisted mainly of pentenals with a different double-bond position. The results of the rearrangement show that the epoxide C-O bond heterolysis takes place mainly on the allyl group side.
- Srednev,Yas'Kina,Moskvichev,Egorova,Shutova,Kozlova
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- Remarkable activity enhancement by trimethylsilylation in oxidation of alkenes and alkanes with H2O2 catalyzed by titanium-containing mesoporous molecular sieves
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Titanium-containing mesoporous materials, Ti-MCM-41 and Ti-MCM-48, have been successfully modified by trimethylsilylation to exhibit enhanced catalytic activity in the oxidation of alkenes and alkanes with H2O2.
- Tatsumi, Takashi,Koyano, Keiko A.,Igarashi, Naoko
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p. 325 - 326
(2007/10/03)
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- Investigation of Aliphatic Dienes by Chemical Ionization with Nitric Oxide
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It is shown that the position of the double bond close to the hydrocarbon end of an aliphatic diene functionalized at C(1) can readily be determined by chemical ionization with NO+.Owing to the low abundance of the ions characteristic for the position of the other double bond, its localization may be difficult.Measurement of the chemical ionization (nitric oxide as reagent gas) spectra of the corresponding epoxides or collision activation studies can help.
- Budzikiewicz, H.,Blech, St.,Schneider, B.
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p. 1057 - 1060
(2007/10/02)
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- ZEOLITES AS CATALYSTS FOR THE CONDENSATION OF ACETALS WITH VINYL ETHERS
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Synthetic zeolites may be used as catalysts for the condensation of acetals and ketals with vinyl ethers, leading to 1,1,3-trialkoxyalkanes.The Nd forms of dealuminized Y zeolites were found to be efficient in this reaction.
- Cheskis, B. A.,Isakov, Ya. I.,Novikov, A. V.,Moiseenkov, A. M.,Minachev, Kh. M.
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p. 809 - 811
(2007/10/02)
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- Mutagen Formation on Photolysis of Dehydroacetic Acid
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Dehydroacetic acid (DHA) gave rise to some mutagenic substances on irradiation with ultraviolet (UV) light.Mutagenicity was detected toward Salmonella typhimurium TA 100 without the S-9 mix.A decrease in the absorbance maximum at 307 nm of DHA was accompanied by a simultaneous increase in total carbonyls and a slight decrease in pH.The mutagenicity of the substances derived from DHA was reduced by the addition of reducing agents, which suggested that the mutagenic substances might be carbonyl compounds.From the results of analysis of carbonyl compounds by GC-mass spectrometry and determination of their mutagenicities in the UV-irradiated DHA sample, it was confirmed that the mutagenicity of the sample was mainly due to 2-pentanal.
- Yamaguchi, Tsutomu
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p. 167 - 172
(2007/10/02)
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- Preparation of α,β-unsaturated aldehydes and 2,7-dimethyl-octa-2,6-dienal
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A process for the preparation of α,β-unsaturated aldehydes by reacting a 1,4-diacyloxyalk-2-ene, which is substituted in the 2-position by an aliphatic radical, with water in the presence of an acid, and of 2,7-dimethylocta-2,6-dienal.
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- Synthesis of 7-Ethyl-5-methyl-4E,8E-undecadien-3-one
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Catalytic hydrogenation of 2-pentyn-1-ol (II) over Lindlar's catalyst provides 2Z-penten-1-ol (III) which on oxidation with pyridinium chlorochromate followed by Grignard reaction with ethylmagnesium bromide furnishes the carbinol (V).The vinyl ether (VI) of V on Claisen rearrangement yields 3-ethyl-4E-hepten-1-al (VII) which on Grignard reaction with methylmagnesium iodide followed by oxidation of alcohol (VIII) gives the ketone (IX), Grignard reaction on IX with vinylmagnesium bromide affords the alcohol (X).Conversion of X into the acetate (XI) followed by saponofication furnishes 5-ethyl-3-methyl-2E,6E-undecadien-1-ol (XII).XII on oxidation followed by Grignard reaction of the resulting aldehyde (XIII) with ethylmagnesium bromide produces the alcohol (XIV), which on oxidation gives the title compound.
- Vig, O. P.,Vig, R.,Dua, D. M.,Puri, S. K.
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p. 1126 - 1128
(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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- Double Bond Stabilizing Abilities of Formyl, Carbo-tert-butoxy, and Carbomethoxy Substituents
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Equilibrium constants for reactions of the type trans-MeCH=CHCH2COX trans-EtCH=CHCOX, where X is H, OMe, and O-t-Bu, have been determined in tert-butyl alcohol solution at various temperatures by using basic catalysts.These equilibrium constants for formation of the conjugated isomer, extrapolated to 25 deg C, are 24, 4.9, and 5.1 for the aldehyde, methyl ester, and tert-butyl ester, respectively.Possible explanations for the relative magnitudes of these equilibrium constants are discussed.
- Hine, Jack,Kanagasabapathy, V.M.,Ng, Peter
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p. 2745 - 2748
(2007/10/02)
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