共查询到20条相似文献,搜索用时 9 毫秒
1.
E. A. Dikusar N. G. Kozlov V. I. Potkin S. K. Petkevich S. N. Sokolov N. V. Kovganko 《Chemistry of Natural Compounds》2003,39(1):11-15
Esters 1b-15b were synthesized by reacting terpenols 1a-7a, sterols 8a-12a, and plant phenols 13a-15a with 3,4,4-trichloro-3-butenyl chloride. 相似文献
2.
E. A. Dikusar N. I. Nechai V. I. Potkin R. V. Kaberdin N. G. Kozlov N. V. Kovganko 《Chemistry of Natural Compounds》2003,39(2):186-190
Previously unknown esters 1b-14b were prepared by reaction of cetyl alcohol 1a, terpene alcohols 2a-6a, sterols 7a-11a, and plant phenols 12a-14a with 4,5-dichloroisothiazol-3-carboxylic acid chloride. 相似文献
3.
E. A. Dikusar V. I. Potkin S. K. Petkevich R. V. Kaberdin N. G. Kozlov A. V. Bazhanov N. V. Kovganko 《Chemistry of Natural Compounds》2004,40(3):230-234
Previously unknown (Z)-3,4,4,4-tetrachlorobut-2-enoates 1b-20b were prepared in 77-88% yields by reaction in the presence of pyridine of 3,3,4,4,4-pentachlorobutanoic acid chloride with cetyl alcohol (1a), terpenols and terpenone oximes (2a-13a), sterols (14a and 15a), diosgenin (16a), and plant phenols and their oximes (17a-20a). 相似文献
4.
F. Shirini N. Ghaffari Khaligh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2156-2165
Abstract Succinimide-N-sulfonic acid (SuSA) is easily prepared by the reaction of succinimide with chlorosulfonic acid. This reagent is able to efficiently catalyze the chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS). All reactions were performed under mild reaction conditions, giving excellent yields. GRAPHICAL ABSTRACT 相似文献
5.
《Analytical letters》2012,45(4):811-825
ABSTRACT The interference of triglycerides in the analysis of sterols and their esters in fats can be eliminated by transesterification of the sample dissolved in n-hexane with a solution of sodium hydroxide 2 mol/L. Since the analytes are distributed equally in n-hexane and in methanol, better results can be obtained by accurate measurements of the volumes, and processing the standards as the samples. Triglycerides and steryl esters are transesterified quantitatively by a solution of sodium hydroxide 2 mol/L using diethyl ether as solvent. At 40°C, ten minutes are sufficient to complete the reaction. The sterols are determined in fats using a mass spectrometer detector, at concentrations as low as 5 mg/Kg. Using FID, it was possible to analyze sterols present in concentrations higher than 100 mg/Kg. 相似文献
6.
E. A. Dikusar N. G. Kozlov V. I. Potkin T. D. Zvereva A. P. Yuvchenko M. P. Bei N. V. Kovganko 《Chemistry of Natural Compounds》2006,42(5):539-542
Previously unreported esters 1b–20b were synthesized from natural terpene alcohols, sterols, plant phenols, and camphar oxime (1a–20a) by reaction with o-carborane-C-carboxylic acid chloride.
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Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 434–436, September–October, 2006. 相似文献
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《Analytical letters》2012,45(9):589-595
Abstract The speed of trimethylsilylation of sterically hindered phenols was increased by promoting the reaction with a small amount of trifluoroacetic acid. Promotion was successful with hexamethyldisilazane, trimethylchlorosilane, bis-(trimethylsilyl)-trifluoroacetamide, bis-(trimethylsilyl)-acetamide, and trimethylsilylimidazole. 相似文献
10.
E. A. Dikusar N. G. Kozlov T. D. Zvereva A. P. Yuvchenko L. A. Mel’nichuk 《Chemistry of Natural Compounds》2004,40(5):472-477
Previously undescribed esters 1b-21b were prepared by reaction of cetyl alcohol 1a, terpene alcohols 2a-16a, plant phenols 17a-19a, and alcohols 20a and 21a with m-C(7)-iso-propylcarboran-C(1)-carboxylic acid.Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 388–392, September–October, 2004. 相似文献
11.
《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
12.
Melamine trisulfonic acid (MTSA) was easily prepared by the reaction of melamine with neat chlorosulfonic acid at room temperature. This reagent can be used as an efficient catalyst for the acetylation of alcohols, phenols, and amines with Ac2O under mild and completely heterogeneous reaction conditions. 相似文献
13.
L. A. Sviridova I. F. Leshcheva G. K. Vertelov 《Chemistry of Heterocyclic Compounds》2000,36(10):1154-1160
Reaction of 1-acetyl-2-phenyl-5-hydroxypyrazolidines with amino acid esters occurs to give the corresponding N-pyrazolidinyl amino acids under mild conditions. 相似文献
14.
A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid. 相似文献
15.
Jianzhong Jiang Li Dai Zhe Cui Liting Lu Zhenggang Cui 《Journal of Dispersion Science and Technology》2014,35(4):524-527
Highly regiospecific mononitration of phenol by NaNO3 and dilute sulfuric acid was carried out in a TX100 oil-in-water microemulsion. Effects of various parameters such as acid type, surfactant concentration, water content, and alcohol have been investigated. The use of inexpensive and relatively nontoxic acidic reagent is an advantage of this method. 相似文献
16.
Hamid Reza Shaterian Fahimeh Khorami Azita Amirzadeh Majid Ghashang Asghar Hosseinian 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2584-2595
Alumina sulfuric acid as a recyclable catalyst conducts the transformation of various types of alcohol, phenols, and oximes with hexamethyldisilazane (HMDS) to the corresponding O-trimethylsilylated compounds in good to excellent yields under mild and ambient conditions with short reaction times. The method is highly selective for the conversion of primary alcohols in the presence of secondary and tertiary alcohols. Additionally, the catalyst can be easily recovered and reused at least eight times without detectable loss of reactivity. 相似文献
17.
Vladislav Arabadzhiev Galin Petrov Erhard T. K. Haupt 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2594-2604
Complexes of lanthanide nitrates (La, Ce, Sm, Gd, Er, and Yb) with tetraethyl and tetraisopropyl esters of bromomethylenediphosphonic acid were prepared. The complexes were characterized by elemental analysis, IR spectroscopy, and, in some cases, NMR. The data confirm that diphosphonates coordinate with two P[dbnd]O groups, and there are no indications for the existence of noncoordinated P[dbnd]O groups. The structure of the complexes depends only on the ionic radius of the central metal atom and not on changes in the electronic or steric behavior of the ester groups. For the complexes of La, Ce, Sm, and Gd nitrates, the formula is LnL2(NO3)3, and for Er and Yb nitrates it is Ln2L3(NO3)6 (Ln[dbnd]La, Ce, Sm, Gd, Er, Yb; L = diphosphonate). 相似文献
18.
目的:为了解宁波地区淡水养殖鱼PAEs污染情况。方法采用液液超声萃取-气质联用法对宁波6个不同养殖点5种淡水养殖鱼体内8种邻苯二甲酸酯含量进行分析。结果宁波地区养殖鱼主要受 DMP、 DEP、 DBP、 DEHP 和 DOP 污染,质量分数最高可达134.1、258.9、249.2、830.8和5029μg/kg;草鱼、鳊鱼、鳙鱼、鲫鱼和乌鳢邻苯二甲酸污染指数PPI分别为9.999、9.735、13.97、8.945和5.809μg/kg。结论宁波地区淡水养殖鱼鱼体邻苯二甲酸酯含量与养殖环境有关,与鱼种无关。 相似文献
19.
Ya‐Ching Shen Chaturvedula Venkata Sai Prakash Li‐Tang Wang Ching‐Te Chien Meng‐Chieh Hung 《中国化学会会志》2003,50(2):297-302
α‐Amyrin margarate ( 1 ), moretenyl margarate ( 2 ) and moretenyl palmitate ( 3 ), three triterpenoid fatty acid esters, have been isolated from the acetone extract of the small twigs of Viburnum odoratissimum in addition to the three known compounds, α‐amyrin palmitate ( 4 ), ursolic acid ( 7 ) and vibsanin‐K ( 8 ). The structures of compounds 1–3 were elucidated based on extensive spectroscopic analysis and alkaline hydrolysis. Preliminary pharmacological studies revealed that vibsanin‐K and ursolic acid exhibited significant cytotoxicity against human gastric (NUGC) and oral epidermoid (HONE‐1) tumor cells at a concentration of 50 μg/mL while compounds 1–3 were inactive. 相似文献
20.
I. V. Ukrainets O. L. Kamenetskaya S. G. Taran I. Yu. Petukhova L. N. Voronina 《Chemistry of Heterocyclic Compounds》2001,37(1):100-102
Different methods of synthesizing esters of 1H-2-oxo-4-hydroxy-3-quinolineacetic acid were studied. Results are given for tests of the anti-inflammatory activity of these products. 相似文献