(5S,6R)-2-(4-甲基)苯基-6-[(1R)-叔丁基二甲基硅氧乙基]-青霉烯-3-羧酸乙酯的合成研究

青霉烯[1]类抗生素是近年来发展很快的一种非典型β-内酰胺抗生素.青霉烯类化合物[2]具有广泛的抗菌活性,具有优于碳青霉烯类抗生素的特点,其固体化合物和酯型前药可口服吸收,不易被β-内酰胺酶水解,同时对脱氢肽水解酶-I( DHP-I )较碳青霉烯稳定.     

青霉烯二茂铁衍生物的合成与抗菌活性研究

为了探寻更具活性的青霉烯类抗生素,设计并合成了8个新的青霉烯二茂铁衍生物,并进行了结构表征与确认.采用琼脂平皿二倍稀释法测定了它们和法罗培南对金黄色葡萄球菌等菌种的最小抑菌浓度(MIC),并对此类化合物的构效关系进行了探讨.结果显示,C-2位被二茂铁基团取代的青霉烯类化合物的抗菌活性优于法罗培南或与其相当,尤其是含有杂环取代基的化合物8h抗菌活性显著.     

光学活性3-(1′-羟基乙基)-4-乙酰氧基-β-内酰胺的立体选择性合成

(1′R,3R,4R)-N-取代-3-(1′-羟基乙基)-4-乙酰氧基-β-内酰胺(3)是合成青霉烯和碳青霉烯类β-内酰胺抗生素的关键中间体.以廉价的L-抗坏血酸为原料,制得S-缩异丙氧叉甘油醛(5),与胺反应定量转变成相应的手性亚胺(6a～6d),6与双烯酮[2+2]环加成反应,高立体选择性地合成3(S)-乙酰基-β-内酰胺(Sa～8d),其非对映体过量由类似反应的80％提高到接近100％.8a经四步反应得到目标化合物3a.     

碳青霉烯类抗生素亲水作用色谱方法研究及其应用

建立了测定人尿液和自来水中4种碳青霉烯类抗生素(比阿培南、美罗培南、多利培南和厄他培南)的亲水作用色谱方法,所用流动相具有较好的质谱兼容性,可用于色谱-质谱联用。以XAmide为色谱柱,考察了乙腈比例、缓冲盐浓度和pH值对4种抗生素保留的影响,提出了可能的保留机理;所发展的方法对目标样品具有良好的线性响应:比阿培南、多利培南和厄他培南的线性范围为0.1~250 mg/L, R²=0.9999;美罗培南的线性范围为0.5~250 mg/L, R²=0.9998; 4种抗生素的定量限(LOQ)为0.1~0.5 mg/L。尿液样品和自来水样品在5 mg/L和25 mg/L两个水平的加标回收率分别为100.4%~111.9%和79.6%~107.4%,相对标准偏差(RSD)分别不大于1%和5%。该方法准确、灵敏、简便,可用于人尿液和自来水中多种碳青霉烯类抗生素的检测。     

反-4-羟甲基哌啶-3-醇的合成

以4-羟甲基吡啶为原料,经苄基保护、硼氢化钠的还原、硼氢化氧化和脱苄基保护等四步反应得到新型5-羟色胺受体激动剂的关键中间体反-4-羟甲基哌啶-3-醇。总收率达55. 7%。产物结构经IR、1H NMR和MS分析确证,并对合成工艺进行了优化。     

α,β-丙烯酸酯立体选择性环氧化

以D-(-)-果糖为手性源,经过丙酮保护、氧化、选择性脱保护、三氟酰化四步反应得到手性酮4。以手性酮4为催化剂,立体选择性环氧化α,β-丙烯酸酯,较高产率和立体选择性地获得了重要的手性中间体α,β-环氧丙酸酯。产率和e.e.值分别达到76%~92%和92%~98%。     

(2S,4S)-苯甲基-2-(6-氟-1H-吲哚-3-羰基)-4-羟基-吡咯烷-1-羧酸酯的合成

以4-羟基-L-脯氨酸为原料,经Cbz保护、偶联、Mitsunobu反应和水解合成了抗肿瘤新药Birinapant的重要中间体--(2S,4S)-苯甲基-2-(6-氟-1H-吲哚-3-羰基)-4-羟基吡咯烷-1-羧酸酯,总收率83%,其结构经¹H NMR和ESI-MS确证。     

2-氨基-5-氟噻唑盐酸盐的合成

以2-氨基噻唑为原料,经Boc保护、溴代、氟代和脱保护成盐反应合成了制备葡萄糖激酶激活剂的重要中间体--2-氨基-5-氟噻唑盐酸盐,总收率55%,其结构经1H NMR表征.     

4-[2-(1-哌嗪基)-4-氨基-6,7-二甲氧基喹唑啉基]-3-甲氧基-D-肌醇的合成

以右旋肌醇甲醚为原料,经缩酮化、磺酸酯化、酸解脱保护、缩合等反应合成了4-[2-(1-哌嗪基)-4-氨基-6,7-二甲氧基喹唑啉基]-3-甲氧基-D-肌醇,此方法具有条件温和、便于操作和产率高等特点。利用波谱分析和元素分析对中间体和标题化合物进行了结构确定。     

普仑司特中间体8-氨基-4-氧代-2-(1H-四唑-5-基)-4H-1-苯并吡喃的合成

以3-氨基-2-羟基-苯乙酮为起始原料，经酰胺化、缩合、环合及脱保护反应合成了普仑司特关键中间体8-氨基-4-氧代-2-(1H-四唑-5-基)-4H-1-苯并吡喃，总收率40.1%，其结构经¹H NMR和MS确证。该路线中脱保护和环合两步反应采用了一锅法，并对合成工艺进行了优化。     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

物质分配系数的测定实验改进

实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。