羟基乙酸

Then we completed the first total synthesis of-Plakoridine A using Eschenmoser couping reaction as akey step. During the synthesis we found the choice of protecting groups and the configuration of the chiralcenter of the substrate play an important role to the key Eschenmoser reaction,so we think our successwould be of guide for synthesizing other polysubstituted pyrrolidines or piperidines.

在论文的第一章中，我们先以易得的对羟基苯乙酸乙酯为原料经多步反应制得了所需的β氨基酸酯，然后利用立体选择性的Aldol缩合反应和内酰胺化反应制得了Plakoridine Alactam，随后，以Eshenmoser缩合反应为关键步骤完成了生物碱-Plakoridine A的首次不对称全合成。

Most sugars, organic acids, phenolic acids and most amino acids increased significantly with elevated CO_2. The treatment, 950±50μmol·mol-1 CO_2 enrichment for 6 h every day had more obvious effects than the treatment, 950±50μmol·mol-1 CO_2 enrichment for 3 h every day. Levan, sucrose, arginine, oxalic acid, alanine, malic acid, acetic acid, lactic acid cinnamic acid,ρ- hydroxybenzoic acid and benzoic acid increased significantly.

CO_2施肥黄瓜根系分泌有机酸、氨基酸、糖和酚酸的总量增加，上、下午均施肥的处理分泌数量最多；CO_2施肥显著促进了果聚糖、蔗糖、草酸、苹果酸、乙酸、乳酸、多数氨基酸、肉桂酸、对羟基苯甲酸和苯甲酸等组分的分泌；单位鲜重根系分泌糖和酚酸的数量增加，多数氨基酸保持不变或降低，但有机酸分泌规律不一致。

Nucleic acids were determined at nanogram levels based on their enhancement effects on the fluorescence reaction system between H 2O 2 and p hydroxyphenylacetic acid catalyzed by Mn [tetrakis(3 N methylpyridiniumy)porphyrin],a mimetic peroxidase.

痕量核酸对meso 四(3 N 甲基吡啶基)卟啉合锰催化H2 O2 氧化对羟基苯乙酸的荧光反应产生增强作用，且增强程度与核酸浓度之间有良好的线性关系，据此建立了测定核酸的高灵敏的荧光分析方法。

METHOD:Venlafaxine was synthesized by steps of etherification,acid chloridization,amidation,Grignard reaction,reduction,salifying from 4-hydrophenylacetic acid.

该化合物以对羟基苯乙酸为原料，经醚华、酰氯华、酰胺化格氏反应、还原、成盐等步骤制备而成。

The objective is to subjugate and discourage the people, because that allows the elite to continue to rule unopposed.

其目的是压制和打击人民的积极性，因为这可以让实权派继续统治不会沦为反对派。

GOD,this is the second time you vanquished me!

天啊，这是第二次你打败了我！