查询词典 hydroxy-ketone

A new unsymmetrical Schiff base zwitterion was synthesized using L -lysine, salicylaldehyde and 2-hydroxy-l-naphthaldehyde.

L-赖氨酸与水杨醛、萘酚醛作用合成了一种不对称希夫碱配体C124H23O4N2Li。

Preparation of the lateral chain-4-benzyloxy-3-hydroxy butyronitrile is introduced as the substrate, the REFORMATSKY reaction is performed, then obtains the dicarbonyl ester, in the structure of which containing a chiral hydroxyl group, then performs the chiral reduction, take off the benzyl group after the protection reaction with acetonylidene,then obtains the lateral chain by oxidation.

手性侧链醛的合成：采用-4-苄氧基-3-羟基丁腈作为底物，通过REFORMATSKY反应缩合得到含有手性羟基的二羰物酯，再手性还原，丙酮叉保护后氢解脱苄，最后氧化得到侧链醛。

The E-TOF will also be feasible and practical to assist chemists in screening the optimal reaction condition or evaluating the overall efficiency of different catalytic systems for a specific asymmetric reaction.4.For the first time,we explored chiralγ-hydroxy-α,β-acetylenic esters,which were prepared via asymmetric alkynylation,as key intermediates to the synthesis of chiralγ-butyrolactones. This convergent and enantioselective approach to chiralγ-butyrolactones is practical and easily handled with protecting group free.

这一概念包括反应产率、对映选择性、配体用量以及反应时间四个重要反应参数，不仅适用同一反应不同催化体系的横向综合性评价，而且适用于某一特定反应催化体系的优化过程，有助于研究人员选择最佳的反应条件。4、我们发展了以手性γ-羟基-α，β-炔酸酯为关键中间体完成了手性γ-丁内酯类天然产物的对映立体选择性全合成，该关键中间体能够以我们的催化体系方便的对映选择性合成，之后的官能团转换方法成熟，易于操作，无需进行繁琐的官能团保护和脱保护过程，绿色经济。

With 1,2-dimethoxyethaneas an additive,the reaction proceeded under mild condition to gave the highly functionalizedγ-hydroxy-α,β-acetylenic esters,and highly toxic reagent was avoided.

以DME为添加剂使不对称合成手性γ-羟基-α，β-炔酸酯的反应条件更加温和、易于操作，避免了剧毒物质的使用。

In the cyclization process,α-acylamino radicals preferred to attack acylsilanes from the face opposite to the β-substituent, and the stereoselectivity of the bridgehead is excellent. The orientation of the hydroxy group formed in the cyclization process was mainly exo.

生物碱架桥上立体化学的建立，可透过环上取代基立体障碍的影响，使得环化过程只会从立障较小的一面进行，因此可得到单一立体化学的结果，而环化所形成的羟基则是以exo的产物为主。

ABSTRACT The thesis aims at the studies on the total synthesis of α-alkylidene -β-hydroxy-γ-butyrolactones.

本论文以α-亚烷基-β-羟基-γ-丁内酯类天然产物的全合成研究为主，包括三个部分：第一部分：文献综述：着重介绍了α-亚甲基-γ-丁内酯萜类，。。。

The combination capacity of THPC was changed with pH and at pH 8.0 the combination amount was the highest with hydroxy and amido groups,although the reaction was weak.

通过对比明胶被THPC、甲醛和铬盐处理后的等电点变化趋势，分析了THPC鞣制效应，最后可确定THPC与皮胶原的鞣制机理。

2-Substituted-3,4-dihydro-1(2H)-isoquinolinones were synthesized from methyl 3-hydroxy-ben- zoates via allyl etherification, Claisen rearrangement, oxidation, reductive amination and aminolysis for the first time.

以3-羟基-4-甲氧基苯甲酸甲酯等为原料，通过烯丙基醚化、Claisen重排、氧化、与伯胺反应、还原、分子内酯的胺解六步反应合成了一系列2-取代-3，4-二氢-1-异喹啉酮类化合物。

Toxicity of four compounds identified as 6a, 12a-dehydro-α-toxicarol, 6a, 12a-dehydro-deguelin,-tephrosin and-6-hydroxy-6a, 12a-dehydro-toxicarol obtained from the leaves and stem of Amorpha Fruticosa and their mixture in a natural ratio 1:2.54:4.18:2.54 were tested against Trematodes grandis.

通过对紫穗槐叶和茎成分分离，得到6a，12a-脱氢－α-灰叶酚、6a，12a-脱氢鱼藤素、灰叶素、6-羟基－6a，12a-脱氢灰叶酚4个化合物。

By chromatographic techniques. On the basis of physico-chemical properties and spectral data, they were identified as α-amyrin,α-amyrin acetate, 27-hydroxy-α-amyrin,β-amyrin,β-amyrin acetate, ursolic acid,β-sitosterol, dauricine, emodin.

中分离得到9个化合物，通过理化性质和光谱分析，分别鉴定为：α-香树脂醇，α-香树脂醇乙酸酯，27-羟基－α-香树脂醇，β-香树脂醇，β-香树脂醇乙酸醇，熊果酸，β-谷甾醇，β-胡萝卜甙，大黄素。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。