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1.
The Preparation of 2 new tetrasubstituted cyclohexane isomers by hydrogenation of diethyl succinyl succinate is reported. A route for their formation is postulated.  相似文献   

2.
Topochemically controlled photochemical dimerization of diethyl succinylsuccinate in the solid is reported. The structure evaluation by elemental and spectroscopic analysis of the product is given. The participation of chelated enols in photochemical cycloadditions in the crystalline solid state is here demonstrated for the first time.  相似文献   

3.
X-ray structure analysis of the title compound (I) is reported. The results are interpreted to predict formation of anti-tricyclo[4.4.01,6.07,12]-1,4,7,10-tetraethoxycarbonyl-3,6,9,12-tetrahydroxy-dodeca-3,9-diene on UV.-irradiation of solid (I).  相似文献   

4.
Abstract

O-Alkylesters of dialkoxyphosphorylthioformic acids were formed in the Arbusov reaction of alkylchlorothionoformates with triesters of phosphorous acid  相似文献   

5.
From thallium(III) bromide solution, the unsubstituted pyridinium cation yields a complex ( 1 ) with the [Tl2Br9]3? anionic stoichiometry. The Raman spectrum and single‐crystal X‐ray crystallographic analysis showed that the salt contains independent [TlBr4]? and bromide anions. A variety of mono‐ and disubstituted pyridinium cations were also employed in similar syntheses. The 2‐bromopyridinium cation gave a salt 2 with [TlBr5]2? stoichiometry, but the crystal structure revealed very weakly interacting [TlBr4]? and bromide anions with a Tl ???Br? distance of 4.1545(6) Å. The 2‐(ammoniomethyl)pyridinium and 2‐amino‐4‐methylpyridinium cations yielded complexes containing [TlBr5]2? ( 3 ) and [TlBr4]? ( 4 ) species, respectively, which were confirmed by Raman spectroscopy and X‐ray crystallographic analyses. For 3 , the [TlBr5]2? anion has a highly distorted trigonal bipyramidal conformation with one long axial Tl ???Br bond of 3.400(2) Å. Microanalytical results in conjunction with Raman spectra from a further five salts confirmed that they all contain the simple [TlBr4]? anion. N? H ???Br Hydrogen bonds clearly influence the nature of the anionic species obtained in these systems.  相似文献   

6.
Although chemical1 and microbiological2 methods for functionalisation of one or more of the bridgehead positions of diamantane are available, there have been no reports of substitution reactions at the methylene positions apart from that of the preparation of diamantanone (1)1 by sulphuric acid oxidation of the hydrocarbon. There are three structural arrangements possible for a non-bridgehead disubstituted diamantane, but the synthetic route described here leads exclusively to 3,5-disubstituted derivatives.

When treated with sodium azide in cold methanesulphonic acid diamantanone (1) underwent a Schmidt fragmentation-recyclisation reaction of the type described by Sasaki et al.,3 yielding a compound which was not isolated but which was presumed to be the keto-mesylate (2) since treatment of the reaction mixture with sodium hydroxide caused a second fragmentation and the final product was the unsaturated acid (3) in 41% yield. The structure of the acid is based on the spectral data and on subsequent chemical transformations. The normal Schmidt rearrangement product, which is probably a mixture of the two possibilities (4) and (5), was also isolated in 50% yield. The unsaturated acid was readily recyclised under acidic conditions. Use of 96% sulphuric acid resulted in the formation of the lactone (6), but use of hot 50% sulphuric acid furnished 5ax-hydroxydiamantan-5-one (7) as the preponderant product (82%). That the hydroxyl-group occupied the axial config-  相似文献   

7.
Complex formation of calcium ions with succinic acid monoamide, methyl hydrogen succinateat 25°C and ionic strength I = 0.3 (KCl) was studied by pH-potentiometric titration. The stability constants ofthe complexes were determined.  相似文献   

8.
9.
Mohamed Abass 《合成通讯》2013,43(15):2735-2757
4-Hydrazino-1-methyl-2(1H)quinolinone (2) was treated with chlorophthalazine, nitrous acid, isothiocyanates and isatines, and also utilized as' a precursor for some new 4-pyrazolylquinolinones. Reaction of 2 with certain 3-acylquinolinones afforded quinolinylpyrazoloquinolinones and/or quinolinylpyrazolylquinolinones.  相似文献   

10.
(4,8,13)-13-Methyl-16-oxo-17-norkaurane-18-carboxylic acid (isosteviol) anhydride is synthesized, which is a first representative of bisditerpene compounds of the kaurane series. The structures of the anhydride and isosteviol chloride were studies by X-ray diffraction and quantum chemistry (AM1).  相似文献   

11.
This article describes some of the exciting results obtained during the study of the gelation behavior of bile acid derivatives in the authors laboratory. The serendipitous discovery of charge-transfer interaction promoted gelation of organic solvents by (steroid)pyrene derivatives/TNF is presented. In this class of molecules, the effect of the location of the chiral center in chiral gelators on the overall chirality of the aggregates in the gel was studied. Also described are the aggregation behavior of bile acid based aqueous gelators which led us to postulate design principals to obtain bile acid based aqueous/organogelators.  相似文献   

12.
Abstract

The reaction of nucleophilic phosphacumulene ylides with visnaginone and khellinone afforded the corresponding phosphanylidene and furochromene derivatives. Moreover, pyranochromenes were obtained from the reaction of chromene carbaldehydes with phosphacumulenes. On the other hand, the phosphanylidene-cyclobutylidenes and their dimers were produced from the reaction of furochromene carbaldehydes with the same phosphonium reagents.  相似文献   

13.
李来才  查东  田安民 《化学学报》2005,63(16):1545-1550
丁二酸脱水法是工业生产丁二酸酐的方法之一. 用量子化学密度泛函理论(DFT)对该反应的微观机理进行了详细研究, 得到了该反应的微观过程. 根据计算和分析可知: 丁二酸脱水制备丁二酸酐的微观反应途径为IM1→TS1→IM2→TS2→IM3→TS3→P+H2O, 在反应过程中IM3为氢键复合物, 整个反应的速控步为IM3→TS3→P+H2O, 其所需活化能为167.17 kJ/mol.  相似文献   

14.
The reaction of 4-hydroxycoumarin and certain aliphatic aldehydes affords 1:1 or complex 2:2 adducts besides (or in place) of the expected 2:1 bis(coumarin) adducts. Reaction with heptanal, cyclohexanecarbaldehyde, and pivalaldehyde are reported as representative. The structure of the reaction products was established by spectroscopical techniques, including X-ray analysis, and their formation was mechanistically rationalized. Some of the 1:1 adducts are synthetically useful for the preparation of 3-alkyl-4-hydroxycoumarins.  相似文献   

15.
A malonylation/decarbalkoxylation sequence from 2-substituted furans was investigated in view of developing a scalable synthesis of hydrophobic nonactic acid analogues.  相似文献   

16.
Summary. A malonylation/decarbalkoxylation sequence from 2-substituted furans was investigated in view of developing a scalable synthesis of hydrophobic nonactic acid analogues.  相似文献   

17.
Summary. A malonylation/decarbalkoxylation sequence from 2-substituted furans was investigated in view of developing a scalable synthesis of hydrophobic nonactic acid analogues.  相似文献   

18.
3-Diazo-2-oxopropionic acid esters and amides react with benzoic and salicylic acid hydrazides to afford 2,3-bis(aroylhydrazono)propionic acid esters and amides having an osazone structure.  相似文献   

19.
20.
《Analytical letters》2012,45(8):1411-1423
Abstract

The electrochemical behaviour of the bilirubin in many kinds of supporting electrolytes on a glassy carbon electrode (GCE) and a hanging mercury drop electrode (HMDE) was investigated by means of anodic or cathodic differential pulse voltammetry. The influences of different methods of pre-treatment of the glassy carbon electrode was also discussed. In Na2B4.O7-KH2PO4 buffer solution, the linear range was 2×10?9-1×10?9 mol/l and the detection limit was 3.3×10?9 mol/l by anodic differential pulse voltammetry at GCE. A linear relationship holds between the peak current and the concentration of bilirubin in a concentration range of 1×10?9-4×10?7 mol/l with good precision and accuracy, and the limit of detection was 2×10?10 mol/l, when cathodic differential pulse adsorption voltammetry at HMDE was used.  相似文献   

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