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1.
Norbornadienes that feature the properties of norbornadiene and of the ene-diyne in the same molecule have been prepared via a simple and high-yielding route starting fromdichlorobicyclo[2.2.1]hepta-2,5-diene (1). 相似文献
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Aaron Balog Marvin S. Yu Dennis P. Curran Guixue Yu Daniel R. Carcanague Youe-Kong Shue 《合成通讯》2013,43(5):935-944
The asymmetric synthesis of multi-gram quantities of a pseudomonic acid precursor is described. Improvements on the literature synthesis of diacetyl arabinal from arabinose are also reported. 相似文献
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A Practical Synthesis of 1,4,7,10-Tetraaza-Cyclododecane,A Pivotal Precursor for MRI Contrast Agents
A practical preparation of the versatile macrocycle 1,4,7,10-tetraazacyclododecane (cyclen) was developed starting from cheap and easily available starting materials as ethylenediamine and glyoxal. 相似文献
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Enzymatic hydrolysis of Dimethyl 2 - (tetrahydropyranyl) hydroxymethyl cyclopropane 1,1 - dicarboxylate 6 with an industrial esterase, followed by a deprotection of tetrahydropyranyl ether affords the title compound in 20% yield. 相似文献
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2,3-Diazido-2,3-dideoxy-beta-D-mannopyranoside derivatives were synthesized in order to prepare beta-glycosides of 2,3-diacetamido-2,3-dideoxy-D-mannuronic acid, a rare moiety of bacterial oligosaccharides. A direct glycosyl donor, 4,6-di-O-acetyl-2,3-diazido-2,3-dideoxy-alpha-D-mannopyranosyl bromide, was prepared, and its synthetic capacity was tested in glycosylation reactions. An indirect route was also elaborated: 3-azido-3-deoxy-beta-D-glucopyranosides were converted into beta-D-mannopyranosides. The cis vicinal diazido function successfully tolerated the conditions of mild acidic hydrolysis, tritylation, Jones oxidation, TEMPO oxidation, acetolysis, and bromination with TiBr(4). 相似文献
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《Tetrahedron letters》1987,28(24):2709-2712
Asymmetric reduction of 3-chloro-2-oxoalkanoates with baker's yeast gave optically active 3-chloro-2-hydroxyalkanoates with ≥95% e.e. in most cases, which were converted to optically active 2,3-epoxyalcohols with ≥78.0% e.e. 相似文献
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《Chemistry & biology》2014,21(3):379-388
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8.
《结构化学》2017,(5)
The reactions of imidazoquinoxaline and 1,3,5-H3 btc acid under different condition have been investigated. The different degree of hydrolysis reaction leads to two different adducts being produced, namely, [(Hdiam Quin)+(H2btc)-](1), and [(diam Quin)4(Imi Quin)·4H2O](2). Both compounds were characterized by X-ray crystallography. Crystal data for 1: monoclinic, space group Pn with a = 9.868(2), b = 5.3172(11), c = 15.387(3) ?, β = 91.10(3)o, C17H14N4O6, Mr = 370.32, V = 807.2(3) ?3, Z = 2, Dc = 1.524 g/cm~3, μ(Mo Kα) = 0.118 mm-1, F(000) = 384, the final R = 0.0385 and w R = 0.0869 for 2294 observed reflections(I 2σ(I)). Crystal data for 2: triclinic, space group P1 with a = 9.825(2), b = 14.144(3), c = 16.054(3) ?, α = 101.06(3), β = 102.55(3), γ = 92.46(3)o, C_(44)H40N_(20)O_4, Mr = 912.96, V = 2128.8(7) ?3, Z = 2, Dc = 1.424 g/cm~3, μ(Mo Kα) = 0.099 mm-1, F(000) = 952, the final R = 0.0554 and w R = 0.1662 for 6563 observed reflections(I 2σ(I)). X-ray diffraction analysis reveals that compound 1 is a salt. Imidazoquinoxaline was wholly hydrolyzed into 2,3-diaminoquinoxaline and protonated as a cation with H2btc-acting as an anion. However, in compound 2, the imidazoquinoxaline is only partly hydrolyzed, and the resulting 2,3-diaminoquinoxaline forms adduct with the intacted imidazoquinoxaline. Both are further aggregated into 3D frameworks by strong hydrogen bonding even π-π interactions. 相似文献
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2,3-dimethoxy-5-hydroxymethyl-6-methyl-1,4-benzoquinone (V) was prepared with a 75 % yield by means of a reaction sequence starting from 2,3,4,5-tetramethoxytoluene via Blanc chloromethylation reaction, Kornblum oxidation, NaBH4 reduction and ceric ammonium nitrate oxidation. The procedure is operationally simple and amenable to gram-scale synthesis. 相似文献
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PreQo (1) is prepared in a 70 % yield by the condensation of chloro(formyl)acetonitrile (2) with 2,6-diaminopyrimidin-4-one (3), and subsequently converted to its amide derivative 5. Isolation of the intermediate 4 in the condensation reaction was also observed giving further insight into the proposed mechanism. 相似文献
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Danilo Annibali Gerhard Ecker Wilhelm Fleischhacker Thomas Helml Wolfgang Holzer Christian R. Noe 《Monatshefte für Chemie / Chemical Monthly》2000,131(4):375-382
Summary. The synthesis of 2,3-disubstituted 2,3-dihydrobenzofuran diastereomers is described. The key step in the reaction sequence
is the chemoselective reduction of a tert. alcohole with tert.-butylamine-borane/AlCl3. The relative configuration of the substituents on the dihydrofurane moiety was assigned via NMR spectroscopy.
Received September 7, 1999. Accepted November 9, 1999 相似文献
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ABSTRACT We report the first stereocontrolled synthesis of the protected lincosamine 2d, the sugar moiety of the clinically important antibiotic lyncomycine.1 To achieve the synthesis of 1, the key structural problem to be solved is the formation of the chiral center C-6 in the D-glycero configuration. In the numerous previous attempts made from D-galactose,2 very little success was obtained as far as stereocontrol is concerned. A fully synthetic route to (±)-methyl-β-lincosaminide was also reported.3 相似文献
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Colin R. Edwards Michael J. Readhead Neil J. Tweddle 《Journal of heterocyclic chemistry》1987,24(2):495-496
A practical synthesis of 2,3-dihydro-2-benzofurancarboxylic acid is reported in five steps and approximately 40% overall yield. The methodology offers a useful new route to 2-substituted-2,3-dihydrobenzofurans. 相似文献
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Luo Mei Liu Shuang Tai Feng Hai Tao Sun Jie Li Qian Rong 《Research on Chemical Intermediates》2012,38(2):499-505
The title heterocyclic 2,3-diaminophenazine (DAP) hydrochloride with the crystallization solvent were obtained from three different routes and their structures were determined by X-ray diffraction, elemental analysis, and IR. 相似文献