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Showing papers on "Benzaldehyde published in 1986"



Journal ArticleDOI
TL;DR: In this article, a transcyclohexyl-4 L-prolinol is transformed into trans-cyclo-hexyl]-4 Lproline via cyclo-3 cyclohexene reduction, on obtient l'on transforme ensuite ensuite en transcycloenyl-3 pyrrolo [1,2-c] oxazolone.
Abstract: La (S)-hydroxymethyl-5 pyrrolidone-2 (preparee a partir de l'acide L-glutamique est condensee avec le benzaldehyde en perhydro phenyl-3 pyrrolo [1,2-c] oxazolone-5; apres alkylation par le bromo-3 cyclohexene puis reduction, on obtient le trans-cyclohexyl-4 L-prolinol que l'on transforme ensuite en trans-cyclohexyl-4 L-proline

135 citations


Journal ArticleDOI
TL;DR: The structure of the benzaldehyde/boron trifluoride adduct has been determined by X-ray crystallography and precise structural information concerning complexes of aldehydes with the above-mentioned Lewis acid remains to be presented.
Abstract: The structure of the benzaldehyde/boron trifluoride adduct (6) has been determined by X-ray crystallography. Accordingly, the Lewis acid BF3 is complexed anti to the phenyl group in benzaldehyde. The B-OC-C fragment lies essentially in a common plane. Anti complexation also pertains in solution, as shown by a heteronuclear Overhauser experiment. MNDO calculations of the acetaldehyde/BF, adduct show that anti complexation does indeed lead to the lowest energy species. However, the syn adduct lies only 1.8 kcal/mol higher in energy. The linear form does not represent a minimum on the energy surface but rather the lowest energy transition state for intramolecular anti * syn isomerization. The calculations of CH,CHO/BF,, of 6, and of the free aldehydes clearly point to LUMO lowering and to an increased positive charge at the carbonyl carbon atom upon complexation. The results are discussed in light of Lewis acid mediated aldehyde additions involving allyl and enolsilanes, stannanes, and cyanotrimethylsilane as well as such processes as Diels-Alder, ene, and Grignard reactions. A wide variety of C-C bond-forming reactions of carbonyl compounds are mediated by Lewis acids such as BF3, AICI,, EtAlCI,, TiCI4, SnC1,. and ZnX,. They include carbonyl additions of allylsilanes, enosilanes, cyanotrimethylsilane, and other silyated' and stannylated* carbon nucleophiles, as well as ene reaction^,^ Diels-Alder addition^,^ and hetero-Diels-Alder cycloconden~at ions.~ It is generally accepted that the Lewis acid activates the carbonyl component by forming an adduct prior to C-C bond formation. Whereas X-ray crystallographic data of a TiCI4 adduct of a chiral acrylic acid ester has recently been reported and discussed with regard to stereoselective Diels-Alder reactions,6 precise structural information concerning complexes of aldehydes with the above-mentioned Lewis acid remains to be presented. N M R , UV, and I R data of common aldehyde/Lewis acid complexes are available, but they do not answer the question of anti vs. syn complexation (1 vs. 2; MX, = Lewis acid).' A great deal of experimental and theoretical work concerning the interaction of formaldehyde with Li+ and other Lewis acids has accumulated ' Philipps-Universitat. 'Universitat Essen. R H KMX"

128 citations



Journal ArticleDOI
TL;DR: Determination of upper pathway enzyme levels in bacteria carrying Tn5 insertion mutant derivatives of plasmid pWW0-161 has shown that the genes for upper pathway enzymes are organized in an operon with the following order: promoter-xylC (benzaldehyde dehydrogenase gene[s],xylA (xylene oxygenase gene)[s], andxylB (benZyl alcohol dehydrogen enzyme gene).
Abstract: TOL plasmid pWW0 specifies enzymes for the oxidative catabolism of toluene and xylenes. The upper pathway converts the aromatic hydrocarbons to aromatic carboxylic acids via corresponding alcohols and aldehydes and involves three enzymes: xylene oxygenase, benzyl alcohol dehydrogenase, and benzaldehyde dehydrogenase. The synthesis of these enzymes is positively regulated by the product of xylR. Determination of upper pathway enzyme levels in bacteria carrying Tn5 insertion mutant derivatives of plasmid pWW0-161 has shown that the genes for upper pathway enzymes are organized in an operon with the following order: promoter-xylC (benzaldehyde dehydrogenase gene[s])-xylA (xylene oxygenase gene[s])-xylB (benzyl alcohol dehydrogenase gene). Subcloning of the upper pathway genes in a lambda pL promoter-containing vector and analysis of their expression in Escherichia coli K-12 confirmed this order. Two distinct enzymes were found to attack benzyl alcohol, namely, xylene oxygenase and benzyl alcohol dehydrogenase; and their catalytic activities were additive in the conversion of benzyl alcohol to benzaldehyde. The fact that benzyl alcohol is both a product and a substrate of xylene oxygenase indicates that this enzyme has a relaxed substrate specificity.

110 citations


Journal ArticleDOI
TL;DR: In this article, the photoreduction of phenylglyoxylic acid (1) in aqueous solution is recommended as a convenient chemical actinometer (φ ≈ 0.6 − 0.8) for the region 250 - 400 nm.

84 citations


Journal ArticleDOI
TL;DR: Both carbonylation and decarbonylation of benzene to benzaldehyde are thought to involve the same initial photochemical step of ligand dissociation to generate a 14e intermediate.
Abstract: The photochemical carbonylation of unfunctionalized arene C-H bonds is catalyzed by various d/sup 8/ complexes under low CO pressure at ambient temperature. The carbonylation of benzene to benzaldehyde is achieved by using IrH(CO)/sub 2/(dppe), IrH/sub 3/(CO)(dppe), or IrBr(CO)(dppe) as the catalyst, and the photoactive species in each case appears to be IrX(CO)(dppe) (X = H or Br). The monodentate phosphine complexes MCl(CO)(PPh/sub 3/)/sub 2/ (M = Rh, Ir) exhibit similar photochemical activity leading to benzene carbonylation. In all cases the amount of benzaldehyde formed is limited by thermodynamics with /Delta/G/sub 298//degree/ = +1.7 kcal. When RhCl(CO)(PPh/sub 3/)/sub 2/ is placed under /sup 13/CO with PhCHO, photochemical decarbonylation is achieved along with significant /sup 13/CO incorporation into the aldehyde, confirming the occurrence of both carbonylation and decarbonylation. Both processes are thought to involve the same initial photochemical step of ligand dissociation to generate a 14e intermediate.

84 citations


Journal ArticleDOI
TL;DR: In this article, the preparation of 2,2-bipyridylchromium peroxide, pyridinechromium permoxide, and chromium peroxy etherate is described.

81 citations



Journal ArticleDOI
TL;DR: The thermal unimolecular decompositions of benzaldehyde (BA), crotonaldehyde (CA), and furfural (FA) have been investigated in a flow reactor at very low pressures by modulated beam mass spectrometry above 1040 K as discussed by the authors.
Abstract: The thermal unimolecular decompositions of benzaldehyde (BA), crotonaldehyde (CA), and furfural (FA) have been investigated in a flow reactor at very low pressures by modulated beam mass spectrometry above 1040 K. Each reaction proceeds by a different mechanism. Whereas BA decomposes by C(O)-H bond fission CA readily undergoes decarbonylation to propene via a three-center transition-state reaction. FA decomposition into vinylketene and CO involves ring opening followed by H-atom transfer in the resulting biradical. Overall high-pressure Arrhenius parameters for the three reactions are derived from kinetic data.

51 citations


Journal ArticleDOI
TL;DR: The mechanism of the reactions of ammonia and benzaldehyde with three different beta-dicarbonyl compounds to form the corresponding dihyropyridines has been followed by NMR as discussed by the authors.

Journal ArticleDOI
TL;DR: In this article, Grignard reagents reacted with 2-aminobenzonitrile to give the intermediate 10, which readily could be cyclized to quinazolines by reaction with carbonyl compounds (e.g. acid chlorides, anhydrides, formates and oxalates).

Journal ArticleDOI
TL;DR: A reagent system CF 3 CCl 3 /Zn(>2 mol)/Ac 2 O transformed aldehydes to 2-chloro-1,1, 1-trifluoro-2-alkenes exclusively as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this paper, a series of aromatic aldehydes have successfully been reduced by N-methylacridan AcH2 in the presence of perchloric acid (HClO4) in a mixture of acetonitrile and acetic acid (MeCN/MeCOOH, 4:1 v v ) at 323 K.

Journal ArticleDOI
TL;DR: In this paper, 3-, 4-Pyridyl and 4-quinolyl Grignard reagents were generated by the reaction of the corresponding phenyl sulfoxides with PhMgBr and give the adducts upon treatment with various aldehydes and ketones.

Journal ArticleDOI
TL;DR: In this article, aldehydes with vanadium acetylides generated from equimolar amounts of vanadium trichloride and acetylenic Grignard or lithium compounds gave α,β-acetylenic ketones via oxidative nucleophilic addition.

Journal ArticleDOI
TL;DR: In this article, the authors present an extension of benzaldehyde aux bore-enolates de cyclopentanone and butanone, which they call butane-cis.
Abstract: Etude a l'aide des calculs MNDO des additions du benzaldehyde aux bore-enolates de cyclopentanone et butanone-cis

Journal ArticleDOI
TL;DR: In this article, a systematic study is presented to quantitate this trend by the solid-state N M R method described here, which should prove to be a powerful tool for studying the structure and fluxional behavior of this interesting class of compounds.
Abstract: Pr)3)2 by neutron diffraction,]' 0.890 A for H2-W(C0)3(PCy3)2 reported here by NMR, and 0.89 A for trans-[Fe(q2-H2)(H)( d ~ p e ) ~ ] B F , by X-ray.3 The latter distance is likely to be in error on the low side as X-ray diffraction will tend to underestimate the distance between the nuclei. A systematic study is currently under way to quantitate this trend by the solid-state N M R method described here. In conclusion dynamic solid-state N M R studies as described here should prove to be a powerful tool for studying the structure and fluxional behavior of this interesting class of compounds.

Journal ArticleDOI
TL;DR: In this article, the side-chain oxidation of alkyl aromatic compounds to either methyl benzoates or orthobenzoic acid trimethylesters can be performed electrochemically at low potentials in methanol solution using an undivided cell and tris(2,4-dibromopheny1)amine as redox catalyst.

Journal ArticleDOI
TL;DR: In this paper, the Mn3+-mediated anodic oxidation of toluene and some substituted toluenes in 60 wt % H2SO4 has been investigated with respect to reaction kinetics and process techniques.
Abstract: The Mn3+-mediated anodic oxidation of toluene and some substituted toluenes (p-chloro-,p-xylene-,p-nitro-) in 60 wt % H2SO4 has been investigated with respect to reaction kinetics and process techniques. The mediators Co3+ in 3.5 N HNO3 and Ce4+ in 60 wt % H2SO4 are compared with Mn3+ in 60 wt % H2SO4 for unsubstituted toluene. The mediated oxidation of the toluenes proceeds in three well-distinguished steps: benzyl alcohol, benzaldehyde, benzoic acid. The last step, which destroys the desired product, the aldehyde, is crucial. Therefore, for continuous resaturation of the electrolyte with toluene and for extraction of benzaldehyde, the benzaldehyde content in the emulgated organic phase has to be kept below a critical value. For toluene,p-chlorotoluene and xylene Mn3+-mediated oxidation only becomes attractive with process temperatures above 60°C. The conversion ofp-nitrotoluene top-nitrobenzaldehyde can only be carried out by Co3+. The reactivities of the oxidants declines in the order: Co3+>Mn3+>Ce4+. Current efficiencies for the recuperation of all oxidants approaches 100%.

Journal ArticleDOI
TL;DR: Synthesis of (E)-7-methyloct-4-en-3-one, a major constituent of the marine sponge Plakortis zygompha, has been carried out using this methodology, and some observations on the mechanism of the reaction between 3-oxobutanoic acid and benzaldehyde are presented.
Abstract: 3-Oxobutanoic acid reacts with aliphatic aldehydes in the presence of pyridine to give α,β-unsaturated methyl ketones in good yields. Analogous results were obtained with a series of other β-oxo acids. Synthesis of (E)-7-methyloct-4-en-3-one, a major constituent of the marine sponge Plakortis zygompha, has been carried out using this methodology. Aromatic aldehydes are generally less reactive under these conditions but give β-ketols when the phenyl ring bears an electron-withdrawing substituent. Some observations on the mechanism of the reaction between 3-oxobutanoic acid and benzaldehyde are presented.

Journal ArticleDOI
TL;DR: Vinyl potassium was formed directly from ethene by use of a new butyl-lithium-potassium t-butoxide-tetramethylethylenediamine metallating reagent; typical products were obtained with 1bromo-octane and, after addition of LiBr in tetrahydrofuran, with benzaldehyde and diphenyl disulphide as mentioned in this paper.
Abstract: Vinyl potassium was formed directly from ethene by use of a new butyl-lithium–potassium t-butoxide–tetramethylethylenediamine metallating reagent; typical products were obtained with 1-bromo-octane and, after addition of LiBr in tetrahydrofuran, with benzaldehyde and diphenyl disulphide.

Journal ArticleDOI
TL;DR: In this paper, a new synthesis of unsymmetrical azines utilizing diethyl phosphorohydrazidate as starting material and based on Wadsworth-Emmons type phosphoramidate approach is described.
Abstract: A new synthesis of unsymmetrical azines utilizing diethyl phosphorohydrazidate as starting material and based on Wadsworth-Emmons type phosphoramidate approach is described.


Journal ArticleDOI
TL;DR: Condensation of pyrrole with benzaldehydes in a mixture of xylene and chloroacetic acid gives a series of substituted tetraphenylporphins with yields exceeding the yields of porphyrins synthesized according to known preparative methods as mentioned in this paper.
Abstract: Condensation of pyrrole with benzaldehydes in a mixture of xylene and chloroacetic acid gives a series of substituted tetraphenylporphins with yields exceeding the yields of porphyrins synthesized according to known preparative methods.

Patent
11 Jun 1986
TL;DR: In this paper, a process for preparing natural benzaldehyde and acetaldehyde and compositions of matter containing NDEs and NCEs as well as products produced thereby and organoleptic utilities therefor is described, which process comprises the step of contacting with base naturally occurring cinnamaldehyde or a natural product rich in cinnamic acid.
Abstract: Described is a process for preparing natural benzaldehyde and acetaldehyde and compositions of matter containing natural benzaldehyde and acetaldehyde as well as products produced thereby and organoleptic utilities therefor, which process comprises the step of contacting with base naturally occurring cinnamaldehyde or a natural product rich in cinnamaldehyde such as Ceylon oil of cinnamon, Ceylon cinnamon bark, Saigon cinnamon bark, cassia oil, Ceylon cinnamon quills, cinnamon leaf oil, oil of cinnamon Madagascar or the like according to the reaction: ##STR1## the reaction taking place in the absence of any other reagents except inert solvent.

Journal ArticleDOI
TL;DR: Organomanganese halides add quite selectivity to aldehydes in the presence of ketones to give the corresponding secondary alcohols in excellent yields as discussed by the authors. But they are not suitable for aldehyde synthesis.

Journal Article
TL;DR: At Atomic absorption spectroscopy confirmed that the simultaneous presence of 5 mM benzaldehyde halved the amount of cell-bound platinum from that measured following treatment with cis-DDP alone, which mitigates the inhibition of DNA synthesis induced by cis-dichlorodiammineplatinum.
Abstract: Synchronized human NHIK 3025 cells were treated with cis-dichlorodiammineplatinum (cis-DDP) either alone or in combination with benzaldehyde as a 2 h pulse in G1-phase. After this pulse, the cells entered S-phase and the rate of DNA synthesis was measured by DNA-flow cytometric recordings of serial samples. After treatment with 10 microM cis-DDP alone, the rate of DNA synthesis was 38% of the control rate. If 3.2 mM benzaldehyde was present together with 10 microM cis-DDP, the rate of DNA synthesis was 56% of the control rate, this being similar to the rate measured following treatment of cells with 5 microM cis-DDP alone. Thus, the simultaneous presence of benzaldehyde with cis-DDP mitigates the inhibition of DNA synthesis induced by cis-DDP. However, when cells were electropermeabilized during the treatment pulse, benzaldehyde did not protect the cells from cis-DDP-induced cell inactivation. The protective effect of benzaldehyde thus seems to reside with the cell membrane and it seems that benzaldehyde, when present together with cis-DDP, partially inhibits the uptake of cis-DDP into cells. Atomic absorption spectroscopy confirmed that the simultaneous presence of 5 mM benzaldehyde halved the amount of cell-bound platinum from that measured following treatment with cis-DDP alone.