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The methyl acetal of methyl phenylglyoxylate has been prepared from halophenylethynes, N-iodosuccinimide and catalytic amounts of (hydroxy(p-tosyloxy)iodo)benzene or p-toluenesulfcnic acid in methanol at room temperature. 相似文献
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Treatment of cycloalkanone dimethyl acetals 3 – 6 with sorbyl alcohol (=(2E,4E)‐hexa‐2,4‐dien‐1‐ol; 1 ) in the presence of acids afforded the novel cycloalkenones 8, 9, 11 , and 13 via a domino reaction (Claisen rearrangement with intramolecular ene reaction and retro‐ene reaction). Cyclopentenone 8 was readily transformed into 14 and 15 , methyl homologues of racemic methyl jasmonate ( 16 ) and methyl dihydrojasmonate (=Hedione®; 17 ), respectively. The organoleptic properties of 14 and 15 are also discussed. 相似文献
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Methyl hydrodisulfide and methyl deuterodisulfide have been prepared in a four-step synthesis. These compounds have been characterized spectroscopically including microwave spectra. 相似文献
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Abstract Methyl (methyl α-D-(9a), α-(9b), β-D-(10a), and β-L-(10b) idopyranosid)uronates were synthesized from myo-inositol. Baeyer-Villiger oxidation of the optically resolved inosose derivatives (3a and 3b) proceeded regioselectively to afford 4a and 4b in high yields, respectively. Ring-opening of the 7-membered hemiacetal-lactones (4a and 4b) with acid and subsequent deprotection gave the title compounds. 相似文献
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胆酸甲酯(甲基)丙烯酰基衍生物的合成 总被引:1,自引:1,他引:0
以(甲基)丙烯酰氯为酰化剂,三乙胺做缚酸剂合成了分子中含有1~3个(甲基)丙烯酰基的胆酸衍生物。结果显示,以酰氯作酰化试剂,胆酸甲酯分子中3个羟基的反应活性顺序是:C3-OH>C12-OH>C7-OH。 相似文献
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Abstract 2,4,5-Tribromostyrene (TBSt) was copolymerized with methyl acrylate (MA) or methyl methacrylate (MMA) in a toluene solution using 2,2′-azobisisobutyronitrile as free radical initiator. The copolymerization reactivity ratios were found to be for the system TBSt / MA r1= 7.4 ± 1.2 (TBSt) and r2= 0.1 ± 1.4 (MA) and for the system TBSt / MMA r1 = 1.8 ± 0.2 (TBSt) and r2 = 0.1 ± 0.2 (MMA). The e and Q values were also calculated. The initial rate of copolymerization, as well as molecular weight of the obtained copolymers for both system linearly increase as the content of TBSt in the monomer mixture increases. Similar behavior has also been established for the course of the copolymerization reactions to high conversions. The resulting copolymers rapidly decompose at temperatures 20–800°C above the decomposition of corresponding (metha)crylate hompolymers. However, the glass transition temperature increases markedly with increasing TBS content. 相似文献
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Onys'ko P. P. Rassukanaya Yu. V. Sinitsa A. D. 《Russian Journal of General Chemistry》2002,72(11):1699-1702
The first example of trifluoropyruvate phosphorylimines was prepared, and its capability for O- and S-amidoalkylation of water, alcohols, and compounds with the SH function was shown. Phenol and 4-methoxyphenol are O-alkylated, while 3-dimethylaminophenol and indole undergo regiospecific C-alkylation at the site of the highest -electron density. 相似文献
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苯胺与氨基甲酸甲酯合成苯氨基甲酸甲酯反应研究 总被引:8,自引:0,他引:8
以无水氯化锌为催化剂,考察了温度、时间、催化剂含量及原料配比等条件对合成反应的影响,确定了最优化反应条件,并初步探讨了反应机理.最佳反应条件下MPC收率可达89.90%,选择性为99.76%. 相似文献
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Z. F. Zoolshoev N. G. Bel'nikevich L. A. Nud'ga V. A. Petrova 《Russian Journal of Applied Chemistry》2005,78(11):1888-1890
A mixed ether, propyl methyl cellulose with varied number of propyl groups, was synthesized from commercial water-soluble methyl cellulose. The effect of the number of side propyl groups on the dynamics of aqueous methyl and propyl methyl cellulose solutions in longitudinal and convergent flows was studied. The conditions under which solutions transform into the induced anisotropic state were determined. 相似文献
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The hydroesterification of acetylene with methyl formate catalyzed by nickel-supported catalysts without any corrosive halide promoter has been comprehensively studied in a fixed bed reactor under various conditions. This reaction can be particularly useful since methyl formate may act as a source of methanol-carbon monoxide, thus simplifying transport and handling[1-3]. The catalysts were prepared by wet impregnation of γ-Al2O3 support with NiCl2 aqueous solution, then dried at 120℃ and calcined at 500℃ 相似文献
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Abstract Both anomers of methyl 1-thio-L-rhamnopyranosides were prepared through methylation of the corresponding isothiouronium salt. 2,3-0-Isopropylidene-, benzylidene-and the until now unknown diphenyl-methylene acetals were synthesized. Phase-transfer catalysed benzylation and LiA1H4-AlCl3-type hydrogenolysis of benzylidene acetals were used to obtain partially benzylated derivatives. Comparing the C NMR data of the synthesized compounds with those of their 0-glycoside analogues revealed that the 0→S exchanges at the anomeric centres caused drastic upfield shifts (~15 ppm) at C-1 and moderate downfield shifts at C-2 and C-5, as well. The chemical shift values of other carbons are not sensitive to the 0→S replacement. 相似文献