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1.
Ever since its isolation in 1820, Quinine has played a crucial role in the development of organic chemistry, chemical industry
and modern medicine. The total synthesis of quinine, widely regarded as an event of epochal importance was claimed by Woodward
and Doering in 1945. This work, however, heavily relied on unsubstantiated literature reports and it appears that Woodward’s
work fell short of a total synthesis of quinine. The first stereoselective total synthesis of quinine was accomplished only
in 2001, by Stork, who incidentally is the originator of the concept of stereoselectivity in total synthesis. Naturally, this
work has been attested as a landmark in organic synthesis by leaders in the field. 相似文献
2.
简单介绍了绿色介质（水、离子液体）中进行的Diels—Alder反应的特点以及反双烯合成在有机化学中的应用前景. 相似文献
3.
为了提高教学质量,培养化学创新人才,文章对有机合成课程建设中存在的问题进行了分析,在有机合成课程教学改革中以"注重能力培养"为核心,采取精选参考教材、整合课程内容、优化教学方法,让长期从事有机合成研究的教师担任主讲教师,控制选课人数,实行小班上课,改进考试办法等一系列举措.通过教学改革实践,提高了学生学习有机合成的积极性,改善了教学效果,对于培养学生的创新能力取得了预期效果. 相似文献
4.
Organic synthesis using clay catalysts 总被引：1，自引：0，他引：1
Gopalpur Nagendrappa 《Resonance》2002,7(1):64-77
Conclusion The clay minerals can catalyze a variety of organic reactions occurring on their surface and interstitial space. Synthetic
organic chemists have been attracted to their tremendous potential as catalysts only relatively recently. Modification of
their properties by incorporating different metal cations, molecules or complexes, can lead to catalysts that are useful in
effecting even more varieties of reactions and higher selectivity in product structure and yield. There is a theory that the
molecules of life actually developed in sedimentary clays. As the organic chemist is becoming more aware of the clay’s efficacy,
its uses in organic synthesis are bound to increase, especially because it helps in developing eco-friendly chemical processes.
The dark clay has a bright future in the area of organic synthesis. 相似文献
5.
李文辉 《荆门职业技术学院学报》2007,22(3):90-96
有机合成是化学研究领域中最具有魅力的。结构复杂、性质多元、应用广泛的有机物及其合成方法学,让人赞叹与探求。文章用科学方法论总结了有机合成中的化学选择性、区域选择性和立体选择性的规律及其热力学和动力学控制策略,提出了综合利用其控制原理解释或预测竞争性反应产物的基本方法。 相似文献
6.
Le Bourg E 《Learning & behavior》2005,33(3):265-276
The learned suppression of photopositive tendencies was studied at the individual level in young flies of both sexes. In a
T-maze, flies had to choose between an arm leading to a lighted vial associated with an aversive stimulus (i.e., a solution
of quinine chlorhydrate deposited on a filter paper in the vial) and another arm leading to a darkened vial free of quinine.
The present experiments were carried out to determine the roles of quinine and relative humidity in the maze. The flies avoided
the lighted vial containing quinine even if they had no tarsal contact with quinine, and this result was not due to any odor
of quinine. Subsequent experiments showed that relative humidity in the lighted vial, and probably in the arm leading to it,
was an aversive stimulus, which partly explains why the flies avoided the lighted vial. However, in conditions in which the
flies had tarsal contact with water or quinine it was confirmed that flies trained with quinine have higher avoidance scores
than those trained with water only. Moreover, individual aversion to humidity was not correlated with the individual avoidance
score: At similar levels of motivation (i.e., similar levels of aversion to humidity), some flies learn to avoid the lighted
vial containing quinine whereas others do not. All these results show that, in addition to quinine, humidity is an unconditioned
aversive stimulus in our paradigm and thus needs to be tightly controlled in experiments of conditioned avoidance. 相似文献
7.
六水三氯化铁催化合成乙酸乙酯 总被引：4，自引：0，他引：4
六水三氯化铁作催化剂，由醋酸和乙醇合成乙酸乙酯，用正交法选出最佳反应条件，经实验验证，产率达86．9％。消除了目前有机化学实验教材中采用的浓硫酸催化法制备乙酸乙酯存在的腐蚀性大、不安全、污染等缺点。 相似文献
8.
A task was designed to teach individual flies to avoid a lighted area after they had displayed an initial preference for it. The flies walked in a T-maze and chose between a lighted and a darkened alley leading, respectively, to a lighted and a darkened vial. Flies that were photopositive on a first trial were subjected to an aversive stimulus (a filter paper inserted into the lighted vial and wetted with a quinine solution), and they performed 16 training trials; they learned to avoid the lighted vial. The flies trained with water instead of quinine in the lighted vial still displayed avoidance of the lighted vial, but to a lesser extent. The flies trained with a dry filter paper in the lighted vial did not show any increase in avoidance during training. Like the flies trained with no quinine at all, those trained to avoid the lighted vial under a partial reinforcement condition (one half of the trials with quinine, the other half with a dry vial) did not master the task. Finally, removal of the quinine after an avoidance acquisition criterion was reached resulted in an extinction process. 相似文献
9.
孙京国 《石家庄职业技术学院学报》2001,13(2):7-8
烯类产品或中间体是有机合成中的一类重要的化合物,制备烯烃化合物时热消去反应具有反应收率高、产物纯度好、产品结构单一等优点.以羧酸酯等为例对热消去反应的机理进行了分析研讨. 相似文献
10.
In two experiments with goldfish patterned after work with rats, consummatory responding for a less preferred food (adulterated with quinine) was measured in subjects that did or did not have previous experience of a preferred (unadulterated) food. The result in each case was not the negative contrast found in rats, but the opposite—more responding in subjects with experience of both foods. The experiments are in accord with a variety of others that have failed to show control of performance by remembered reward in goldfish. 相似文献
11.
Dennis A. Vanderweele 《Learning & behavior》1974,2(4):309-312
Mongolian gerbils (Meriones unguiculatus) were examined for components of thirst in the laboratory. The gerbil, reputed to be a desert-adapted rodent, was tested for its response to quinine adulterations of water, hypertonic solutions (1 M sodium chloride, NaCl), and hyperoncotic solutions (40% W/V polyethylene glycol in isotonic saline, PG). Both NaCl and PG were administered intraperitoneally. Gerbils accepted quinine when it was the only solution available and food was ad lib, but preferred distilled water to quinine if both were available. Both PG and NaCl produced increased water intakes in gerbils within the first 2 h, postinjection. PG, however, produced the most reliable and largest increase in water consumption, illustrating that extracellular dehydration is probably a more significant thirst stimulus in gerbils. 相似文献
12.
计算机技术为教学改革提供了良好条件，它调动了教师与学生两个积极性，使课堂教学的知识性与趣味性有机结合起来。目前多媒体教学在实践中远远没有发挥其优势，素材库的开发落后于实践的需要，教师运用计算机技术进行教学的积极性不高，我国计算机辅助教学还没有形成自己的符合中国国情的基础理论。教育行政主管部门及学校应加强组织指导，注意研究把传统教学手段与多媒体教学手段的优势结合起来，加强校园网络建设、推动计算机辅助教学的发展。 相似文献
13.
以丙醇锆为锆源,有机小分子三乙醇胺作为络合稳定剂和模板剂,通过水热合成途径制备了二氧化锆介孔分子筛.利用X射线粉末衍射和低温N2吸-脱附法等表征手段,考察了TEA加入量对二氧化锆介孔分子筛结构的影响,并探析了TEA在介观结构形成过程中的作用机理. 相似文献
14.
彭腾 《宁波职业技术学院学报》2007,11(4):22-25
社会主义产品经济是马克思设想的按劳分配的经济基础和逻辑起点.我国现阶段根本不具备马克思所讲的按劳分配的前提条件,因此,我国现阶段的按劳分配表述的是与马克思不同的内涵,其实质上是按生产要素贡献分配即按劳动力贡献分配.在我国社会主义现阶段,客观经济条件决定了我们还必须坚持按劳分配与按生产要素分配的有机结合. 相似文献
15.
With increasing research interests in the field of light-matter interactions,various methods have been developed for regulating nonlinear optical (NLO) materials.However,the design and synthesis of organic molecular materials for second-order nonlinear optics remain a great challenge because of the strict requirement of the materials to possess a noncentrosymmetric structure.In this work,two benzothiadiazole (BTD) derivatives referred to as BTD-H and BTD-F were synthesized,and their NLO properties in the crystalline states were studied.It was found that introducing fluorine into the BTD backbone effectively tuned the crystal packing styles of BTD derivatives to a noncentrosymmetric system for effective second-order NLO responses.Such a strategy to induce the noncentrosymmetric structure by introducing the fluorine atoms and halogen interactions may provide guidance for future engineering of organic NLO molecular materials. 相似文献
16.
17.
烯酮作为一种化学性质非常活泼的有机试剂,其理论与应用研究近年来取得了令人瞩目的进展。本文介绍了烯酮的结构、制备及其在有机合成中的应用。 相似文献
18.
G. Nagendrappa 《Resonance》2010,15(9):779-793
Today we cannot imagine our lives without a variety of colours. Every colour we see, consume, enjoy, apply and use wherever
we need has a dye associated with it. More than 90% of the thousands of dyes used now are synthetic. A little more than 150
years ago a handful of dyes of only natural origin were available. In 1856 the era of synthetic dyes was ushered in by a spirited
young chemist, William Henry Perkin, when he was trying to synthesize quinine, but obtained a coloured substance instead.
It was a much desired colour and therefore became an instant hit. The following is an account of Perkin’s life as a chemist
and an industrialist par excellence. 相似文献
19.
刘传银 《郧阳师范高等专科学校学报》2002,22(3):76-79
有机合成是大学有机化学的一个重点和难点 .在有机合成中一些不能用常规反应合成的有机化合物可以通过极性转换的方式来完成 .极性转换包括羰基化合物、烃类及胺类化合物的极性转换 ,极性转换试剂的合理应用是达到目标合成物的重要一环 .合理运用极性转换方法可以帮助学生熟练掌握有机合成 相似文献
20.
N. R. Krishnaswamy 《Resonance》1996,1(1):56-62
A naturally occurring organic compound has been chosen to illustrate (a) structure determination by chemical and spectroscopic methods, and (b) synthesis and chemical transformations. 相似文献