对映异构的

The results show that catechin stereoisomers possess the same fragmentation pathways and cannot be differentiated even in MS spectra.

发现儿茶素对映异构体间具有相同的质谱裂解途径，多级质谱无明显区别。

Diastereomers of cinchonine and cinchonidine were separated in pressure-assisted capillary electrochromatography mode, and the resulted separation efficiency was much higher than that obtained in high performance liquid chromatography.

采用压力辅助电色谱模式拆分了非对映异构体辛可宁和辛可尼丁，其柱效远高于其在HPLC中拆分的结果。

It is demonstrated that the chiral quaternary ammonium salts catalysts exhibit promising catalytic properties for the substrate. Part III: The synthesis and the characterizing of the macroporous aminomethyl resin-supported cinchona alkaloid complexes and the study on its catalytic properties The part consists of two subsections. the macroporous aminomethyl resin -supported cinchona alkaloid complexes were synthesized by the stuff (cinchonine, quinine and macroporous aminomethyl resin). Their structures were characterized by means of elemental analysis, XPS, TG/DTA; the chiral polymer-supported complexes were first used as catalysts for the reduction of ketones. Their catalytic properties for the reduction processes were investigated. The comparison of the products e.e., the conversion of the substrate among different reduction processes was employed with determined by HPLC. The effects of the time, the temperature, the ratio of catalyst to substrate, reaction solvent as well as the recycle times were also discussed.

第三章聚-4-氨甲基苯乙烯负载金鸡纳碱金属络合物的合成与表征及其不对称催化性能研究本章分为两节，以辛可宁和奎宁及聚-4-氨甲基苯乙烯为原料，合成了4种聚-4-氨甲基苯乙烯负载金鸡纳碱络合物催化剂，并对它们的结构用元素分析、X-射线光电子能谱、TG/DTA等几种测试手段进行了表征；首次将所合成的手性高分子负载的金属络合物用于催化芳香酮不对称还原反应，详细研究了所得的手性高分子负载的金属络合物对不同底物的催化性能，用HPLC等分析手段定量检测了还原过程的底物转化率及其产物对映异构体选择性，并考察了反应时间、反应温度、催化剂和底物投料比、反应溶剂和循环次数对催化性能的影响。

Objective: To develop a method for purity test and enantioseparation of ephedrine levorotatory by capillary electrophoresis.

目的：建立左旋麻黄碱中对映异构体杂质检查的毛细管电泳方法。

Clausenamide is a compound isolated from clausena lansium Skeels, and has been synthesized and resoluted into levorotatory and dextorotatory clausenamide by our chemists.

黄皮酰胺是从芸香料黄皮属植物黄皮叶中分离出的化合物，我所合成室已完成它的全合成并应用拆分技术分离出它的对映异构体。

This intermediate is responsible for the stereoselective nucleophilic substitution and the subsequent racemization of 3-EtO-NDZ enantiomers in acidic ethanol.

该中间体导致了3-EtO-NDZ对映异构体在酸性乙醇中所发生的立体选择性亲核取代反应及随后的消旋过程。

Their diasteroisomers were achieved because the group of alkoxy assaulted C_1 of 2-deoxyribofuranosyl chloride from different directions.

因烷氧基可从呋喃脱氧糖环的不同方向进攻1-位碳原子，因而所得到的烷基呋喃脱氧戊糖苷是一对非对映异构体。

We selected different eluents according to different diasteroisomers and gained the singles of the diasteroisomers by the column chromatography.

经过简单易行的薄层色谱分析法选择了不同的洗脱剂，然后通过柱色谱分离，得到了多对非对映异构体的α-体和β-体。

Synthesis of such compounds from nonchiral materials results in equal numbers of the enantiomers, racemates.

使用非手性物料合成此类化合物导致等量的对映异构体和外消旋物。

Finally, we demonstrate the transformation of β-hydroxy nitriles to a variety of diastereomerically pure and highly functionalized acyclic and heterocyclic γ-amino alcohol derivatives.

最后， 本文介绍了由β-羟基腈向各种纯非对映异构体，多功能性的开环和杂环γ-氨基醇衍生物的转化反应。

They weren't aggressive, but I yelled and threw a rock in their direction to get them off the trail and away from me, just in case.

他们没有侵略性，但我大喊，并在他们的方向扔石头让他们过的线索，远离我，以防万一。

In slot 2 in your bag put wrapping paper, quantity does not matter in this case.

在你的书包里槽2把包装纸、数量无关紧要。