查询词典 aldehydes

In chapter three, the activating agents of ytterbium have been examined. Barbier-type reaction promoted by ytterbium metal was examined. The experimental results shown that the yield of Barbier reaction of imines with allylic bromide promoted by ytterbium is higher than that of aldehydes and ketones with allylic bromide under the same reaction conditions. In this chapter, the reductive cleavage of Se-Se and S-S bond induced by ytterbium metal was also studied.

首先研究了金属镱的活化剂以及活化方法，接着考察了金属镱促进的Barbier反应及其在合成高烯丙基胺和高烯丙基醇中的应用，以及影响该反应的主要因素；究了金属镱促进的二硫醚和二硒醚的S—S键和Se—Se键的还原断裂，继而与氯代烃，胺基甲酰氯反应生成相应的硫醚，硒醚，胺基甲酸硫代酯和硒代酯。

Polar compounds, such as dihydro-alkyl furan-one, furandione, benzofuran, benzosazol, aldehydes and esters were also detected.

对部分极性化合物分析，检出了二氢烷基呋喃酮系列、呋喃二酮、苯并呋喃及少量醛类和酯类化合物。

There is no effective catalytic asymmetricsystem reported for the HDA reaction between Brassard diene with aldehydes tosynthesize δ-lactones.

由 Brassard 二烯与羰基化合物的反应生成δ-内酯的研究近乎空白。

The Mannich reaction of butanone, aromatic aldehydes and aromatic amines.

对-甲苯乙酮与芳香醛和芳香胺的Mannich反应。

The results showed that the first canonical correlation coefficient between aldehydes, ketones, esters and the total quantity of each kind of ingredient and smoking quality achieved 5 % or 1 % remarkable level. And their correlation depended mainly in the correlation between phenylacetaldehyde, furfural, megastigmatrienone-1, megastigmatrienone-3, geranylacetone,β-damascenone, keto-isophorone, dihydroactinidiolide and smoking quality.

结果表明：醛类成分、酮类成分、酯类成分与香气质、香气量的第一典型相关系数达到5%或1%显著水平，各类成分总量与香气质、香气量的第一典型相关系数达到1%极显著水平，其相关关系主要表现在苯乙醛、糠醛、巨豆三烯酮1、巨豆三烯酮3、香叶基丙酮、β-大马酮、氧化异佛尔酮、二氢猕猴桃内酯等成分与香气质、香气量的相关上。

These dendritic NOBIN derived Schiff base ligands have been applied to titanium catalyzed hetero-Diels-Alder reaction of Danishefshy's diene and aldehydes, affording the corresponding 2-substituted 2, 3-dihydro-4H-pyran-4-one in quantitative yields and excellent enantioselectivities (up to 97. 2%ee). Comparing the reactivities and enantioselectivities of reaction catalyzed by the titanium complexes of these Schiff base ligands, it was found that a series of ligands L〓 were superior to the other three series of ligands L〓, L〓 and L〓, a significant positive NLE and a dendrimer effect existed in the L〓 dendritic catalyst system. The disposition of the dendritic wedges and the dendron size in the ligands were observed to have a significant impact on the enantioselectivity of the reaction.

NOBIN衍生的树枝状大分子希夫碱手性配体与钛形成的配合物在催化不对称杂Diels-Alder反应中的应用将得到的四个系列NOBIN衍生的树枝状希夫碱三齿手性配体与四异丙氧基钛形成的配合物用于催化Danishefsky's diene与醛的不对称杂Diels-Alder反应，通过反应条件的优化，获得了定量的收率和最高达97.2％ee值的对映选择性；考察了这四个系列NOBIN衍生的树枝状希夫碱钛配合物的催化活性和对映选择性，结果发现它们的活性次序依次为L〓≈L〓＞L〓＞L〓，对映选择性次序依次为L〓＞L〓＞L〓＞L〓。

Most of researches focused on the HDA reaction betweenDanishefsky diene with aldehydes.

其中又以 Danishefsky 二烯与羰基化合物的反应研究最为详尽。

Simultaneously, we proposed the working model of assembled dendritic catalyst for HDA reaction of Danishefsky's diene with aldehydes.

同时也考察了Dendrimer取代基的大小、位置对产物收率与对映选择性的影响，结果发现L〓系列表现出较明显的Dendrimer效应。

This two-step procedure provided 55 out of 76 dipeptide aldehydes, and 26 were with purity up to 80%.

3，6-二取代-5，6-不饱和-2-哌嗪酮化合物库的制备。

In this thesis, for the first time, we attempted at preparing a library of 20×20 dipeptide aldehydes based on 20 natural amino acids by parallel solution phase method.

本论文以20个天然氨基酸为原料，利用液相平行合成技术进行了一个20×20的二肽醛化合物库的系统合成的尝试，并进一步合成了3，6-二取代-5，6-不饱和-2-哌嗪酮化合物库。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。