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Abstract In this study we are interested in the synthesis of vinylbenzyl esters of amino acids. A method previously described in the literature has some disadvantages. We tried to find a better one. Three methods were tested and four amino acids were used. The best one consists of alkylation with an alkyl halide. The yield for this synthesis reached 96%. In all the case the products obtained were characterized by IR, NMR, and mass spectroscopies. The optical purity of the products was determined by polarimetry or by an NMR shift study. The ability of this type of monomer to polymerize and copolymerize was tested. 相似文献
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Khadija Raouf-Benchekroun Claude Picard Pierre Tisnés Louis Cazaux 《Journal of inclusion phenomena and macrocyclic chemistry》1999,33(4):415-425
The extraction and transport properties of macrocyclic dioxa-, dithia- and diazatetralactams are reported along with those of open-chain analogous compounds. The preference of three of them for lead over alkali, alkaline-earth or other heavy metal cations is discussed. 相似文献
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Ohne Zusammenfassung 相似文献
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4-Hydroxy cinnamic esters, thiolesters, aldehydes and alcohols, or related compounds, implied in the biosynthesis of lignins are easily synthesized in good yields from iminium salts of coumaric , ferulic and sinapic acids. No prior protection of the phenol group is needed in this method. 相似文献
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P. Maroni L. Cazaux J. P. Gorrichon P. Tisnes J. G. Wolf 《Magnetic resonance in chemistry : MRC》1973,5(11):523-528
The empirical calculation of chemical shifts of methyl-1,3-dioxans leads to consistent results. Deviations from the experimental value are correlated with ring deformation. This method is applied to 4 or 6-ethyl, -isopropyl and tertiary butyl-1,3-dioxans. With no substituent at C5, the 4-tertiary butyl group causes no more deformation than at the 2 or 5 position. Interactions of this group with one or two methyl groups at C5 are examined. 相似文献
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X-ray induced Auger electron spectroscopy can be applied to the chemical analysis of thin samples with a spatial resolution in the 10 μm range. The first experimental results obtained with various anode materials and various samples are reported. The signal intensities (in the range of 103 counts/s) are similar to those obtained by using a conventional electron spectrometer with a resolution in the millimeter range. Theoretical considerations together with the results obtained make it possible to evaluate the sensitivity of this technique and suggest how the spatial resolution can be improved further (20 μm at present, 2–3 μm in the near future). The radiation damage and sample thickness constraints of this new technique and of conventional Auger electron spectros- copy are compared. Application of X-ray induced Auger analysis to biological objects is suggested and the effect of the present results on scanning X-ray radiography and characteristic X-ray absorption microanalysis is also pointed out. 相似文献
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Louis Cazaux Christiane Vidal Maurice Pasdeloup 《Magnetic resonance in chemistry : MRC》1983,21(3):190-195
Two 1,4-benzodiazepinones of psychopharmacological interest, pinazepam (2) and prazepam (3), were studied in solution by 13C and 1H NMR. 1H variable-temperature experiments showed that the seven-membered ring exists in a simple pseudo-boat form at room temperature, but the energy barrier is higher in 3 (ΔG405°c = 82.8 kJ mol?1) than in diazepam (1). Moreover, upon addition of LSR, the boat conformation is retained in the lanthanide ion-substrate complex, as with 1 in the solid state. Using a concentration-dependent shift technique and a computer-assisted LIS method, the conformations of the N-branched side-chain were investigated. Two preferred orientations were found for the propargyl group of 2, while three unequally populated conformations of the cyclopropyl moiety of 3 are distributed preferentially in the sterically unhindered space around the complex. 相似文献
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Three chiral macrocyclic dilactones containing L-glutamic or L-cystine moiety are synthetised by a simple method based on a tin “template-driven” process. Complexing properties are examined. 相似文献
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J. Cazaux 《Surface science》1984,140(1):85-100
The sources of background noise in Auger electron microanalysis are analyzed in order to evaluate the minimum detectable concentration xm and the minimum number of detectable atoms ym that can be reached. The best choices of operating conditions (the energy E0, intensity I0, and spot size d0 of the incident electron beam, and the duration of the experiment te) are deduced for bulk and thin film analysis. The main results are: (i) The choice of E0 is not very stringent, at least when E0 ? 5Ei(A), where Ei(A) is the ionization energy, (ii) For a given electron dose received by the sample, xm is improved by the use of the largest incident spot size while ym is improved by the use of the finest spot size. The results also hold for other microanalytical techniques such as electron energy loss spectroscopy or electron probe microanalysis. (iii) Chemical identification of a single atom will be possible on samples able to tolerate very large electron doses by using incident electron beams 10 nm or less in diameter. The expected performance of a coincidence technique first suggested by Wittry is also discussed. 相似文献