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1.
Summary Gas chromatographic chiral separation of several chiral 2-and 3-alkanols and diols was studied both in their free hydroxyl
and in their trimethylsilyl ether forms. First, the derivatization procedure was verified through the identification of the
trimethylsilyl ethers formed on the basis of their mass spectra and optimized to obtain quantitative reaction. The optimized
procedure was applied to the trimethylsilylation of racemic mixtures of various hydroxyl compounds. The silylation was found
to be highly effective in the improvement of the separation of the individual enantiomers. The major advantages of the derivatization
process can be summarized as: (i) excellent baseline separation of the enantiomers of the silyl ethers was achieved in contrast
to the parent OH-containing compounds, (ii) the sensitivity of detection highly increased, (iii) the separations do not show
any significant concentration dependence and finally (iv) the analysis time needed decreased significantly.
Presented at: Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 3–5, 1997 相似文献
2.
The “one-pot” homogeneous hydrogenation of γ-butyrolactone and succinic or fumaric acid to 1,4-butandiol, have been successfully realized in the presence of the catalytic system [Ru(acac)3]/triphos] [triphos:MeC(CH2PPh2)3]. The influence of some reaction parameters on the regioselectivity and the rate of the reaction were investigated. The study was then extended to the “one-pot” synthesis of isotopomeric 1,4-butandiols by deuteration of the appropriate substrates in a deuterated solvent. 1,4-butandiol-d8, which was fully characterized, was obtained with 96% yield and 100% isotopomeric selectivity. A mechanism was proposed to rationalize the role of catalyst, solvent and deuterium distribution. 相似文献
3.
Dr. Rongli Mi Dr. Lingzhen Zeng Maolin Wang Shuheng Tian Jie Yan Shixiang Yu Dr. Meng Wang Prof. Ding Ma 《Angewandte Chemie (International ed. in English)》2023,62(28):e202304219
The utilization of carbon resources stored in plastic polymers through chemical recycling and upcycling is a promising approach for mitigating plastic waste. However, most current methods for upcycling suffer from limited selectivity towards a specific valuable product, particularly when attempting full conversion of the plastic. We present a highly selective reaction route for transforming polylactic acid (PLA) into 1,2-propanediol utilizing a Zn-modified Cu catalyst. This reaction exhibits excellent reactivity (0.65 g gcat−1 h−1) and selectivity (99.5 %) towards 1,2-propanediol, and most importantly, can be performed in a solvent-free mode. Significantly, the overall solvent-free reaction is an atom-economical reaction with all the atoms in reactants (PLA and H2) fixed into the final product (1,2-propanediol), eliminating the need for a separation process. This method provides an innovative and economically viable solution for upgrading polyesters to produce high-purity products under mild conditions with optimal atom utilization. 相似文献
4.
Rajendra P. SinghJean’ne M. Shreeve 《Journal of fluorine chemistry》2002,116(1):23-26
Various fluorinated chiral compounds were synthesized using bis(2-methoxyethyl)aminosulfur trifluoride (Deoxofluor) as a nucleophilic fluorinating reagent. Reactions of Deoxofluor (1) with amino alcohols (2a-d) and diols (2e-g) in methylene chloride at room temperature led to the formation of the corresponding fluoro derivatives (3a-g) in good yields. 相似文献
5.
《合成通讯》2013,43(12):2003-2009
Abstract Primary alcohols and diols are easily oxidized to methyl esters by a solution of trichloroisocyanuric acid with methyl alcohol in dichloromethane. In addition, α,ω-diols are also readily oxidized into lactones by refluxing with trichloroisocyanuric acid and pyridine in dichloromethane. 相似文献
6.
Marta Teijeira Yagamare Fall Francisco Santamarta Emilia Tojo 《Tetrahedron letters》2007,48(45):7926-7929
A new efficient and rapid experimental method and product isolation procedure as well as easy recyclable reaction media is expected to contribute to the development of a green strategy for the synthesis of furan diol from d-glucal. We determine the best conditions of reaction, minimizing the toxicity and finding an environmentally more acceptable process, using [Bmim][MSO4]/InCl3·3H2O as a new solvent system under extremely mild conditions, providing high yields with a dramatic enhancement of reaction rate. 相似文献
7.
A facile one-pot synthesis providing vicinal diols and 1,3-diols in >95% stereoisomeric purity from commercially available enantiopure hydroxy esters has been developed. The esters were reduced with DIBALH and alkylated in situ with 4-pentenylmagnesium bromide, which after workup generated the title diols as diastereomeric pairs. These pairs were easily separated by preparative chromatography, affording products with retained stereoisomeric purity from the starting materials. This method represents an expedient preparation of many common natural products, such as cerambycid beetle pheromones and intermediates towards bicyclic acetal bark beetle pheromones. 相似文献
8.
Yu. S. Zimin N. V. Trukhanova R. R. Shamsutdinov V. D. Komissarov 《Reaction Kinetics and Catalysis Letters》1999,68(2):237-242
The kinetics of the oxidation of diols by ozone was investigated by a spectrophotometric method in the temperature interval
of 277–304 K. The activation parameters of the reaction were determined. 相似文献
9.
Wanda Ziemkowska Romana Anulewicz-Ostrowska 《Journal of organometallic chemistry》2004,689(12):2056-2065
The dependence of the structure of complexes of sterically crowded 2,4-dimethylpentane-2,4-diol with group 13 metals trialkyls on the kind of metal, as well as steric bulk of the substituents on the metal atoms is reported. The reaction of tBu3Ga with 2,4-dimethylpentane-2,4-diol leads to the formation of an unstable dimeric product {tBu2Ga[(OC(CH3)2CH2C(CH3)2OH]}2 (1) possessing a four-membered Ga2O2 core and two unreacted hydroxyl groups. Compound 1 undergoes further intramolecular reaction to yield the unusual (monoalkyl)gallane O,O′-chelate complex {tBuGa[OC(CH3)2CH2C(CH3)2O]}2 (2). In contrast to tBu3Ga, tBu3In reacts with 2,4-dimethylpentane-2,4-diol to give the stable dimeric complex tBu4In2[OC(CH3)2CH2C(CH3)2OH]2 (4) stabilised by two intramolecular O-H?O bonds. At higher temperature compound 4 reacts with an excess of tBu3In to form the trinuclear complex tBu5In3[OC(CH3)2CH2C(CH3)2O]2 (5). The reactions of 2,4-dimethylpentane-2,4-diol with trialkylmetallane with small alkyl groups, i.e. Me3Ga and Me3In allow for the isolation of the trinuclear diolates {Me5M3[OC(CH3)2CH2C(CH3)2O]2} [M=Ga (3), M=In (6)]. The crystal structures of 2, 3 and 4 have been determined by single crystal X-ray diffraction. The reactions of tert-butylmetallane diolates with trimethyl metallanes have been studied. The interaction of the allane complex {tBuAl[OC(CH3)2CH2C(CH3)2O]}2 with Me3Al results in the formation of the trialuminium mixed-ligand product {Me3(tBu)2Al3[OC(CH3)2CH2C(CH3)2O]2} (7). Compounds 2 and 4 undergo a total transmetallation reaction in the presence of Me3M to yield [Me5M3(diol-(2H))2] [M=Al, Ga] products. 相似文献
10.
Daniele Marton Diego Stivanello Giuseppe Tagliavini 《Journal of organometallic chemistry》1997,540(1-2)
Butane-2,3- (1a), pentane-2,4- (1b) and hexane-2,5-dione (1c) react with Bu2(CH2=CHCH2)SnCl in the presence of water to give monoallylated keto-ols (2a, 2b) and/or diallylated diols (3a, 3b, 3c), this depending upon the employed molar ratio [diketone]/[allyltin chloride]. Bu(CH2=CHCH2)SnCl2 reacts with neat 1c in a one-pot synthesis to give mixtures of heterocyclic compounds: 2,5-diallyl-2,5-dimethyltetrahydrofuran (4), and 3-chloro-1,5-dimethyl-8-oxabicyclo [3,2,1] octane (5). Compound 4 is also obtained in high yield from the corresponding diol 3c by cyclodehydration promoted by RSnCl3 (R = Me and Bu). 相似文献