研究发现，降低温度是对蔗糖C6位最活泼羟基进行单一选择性保护的有效方法。
The temperature reduction was shown to be an effective method for the most active C 6 hydroxy mono protection.
研究表明，棓酰类多元酚可与铝形成络合物，其络合物是铝和棓酰基中苯三酚的邻位二羟基形成的，它是稳定的五员螯合环结构；
It is show that the complexes of galloyl type hydrolysable tannins with aluminum are formed which involve five-member ring stably formed adjacent hydroxyl groups in galloyl to aluminum atoms.
所有的K离子均同时与酚羟基和硝基的氧原子配位。
All K atoms coordinate with o atoms of phenolic hydroxyl group and nitro-group simultaneously.
对配体进行量化计算的结果表明，羰基氧、羟基氧是可能的配位原子，与结构推测结果相吻合。
The results of the quantum chemistry calculation of the ligand indicate that the carbonyl and hydroxyl oxygen atoms maybe coordinate to the metal atom, which is consistent with the conjecture by IR.
随着反应时间的延长，有羟基邻位和对位双硝基化以及羟基两个邻位双硝基化产物生成。
Dinitrations occurred at two ortho-positions or both ortho- and para-positions to the hydroxy group with longer reaction time than mononitration.
分开的卤化物从第二个水分子得到一个质子，同时产生的羟基配合体与乙烯反应，留在了金属的配位区内。
The departing halide extracts a proton from the second water and the generated hydroxyl ligand reacts with the ethylene, while remaining in the coordination sphere of the metal.
结果表明金属离子与其中的葡萄糖基、羟基、羧基、胺基等配位基发生了配位反应。
Results indicate the metal ions have coordinated with thereinto glucose, hydroxy, carboxyl, amidocyanogen etc.
添加有配位倾向的含羟基的化合物会加快破胶过程。
Addition of the compounds with hydroxyl groups and a tendency of coordination will accelerate the degradation.
羟基磷灰石(HA)晶须具有较低的位错密度，较高的抗拉性能，可用作生物陶瓷的增韧材料。
Hydroxyapatite (ha) whisker has lower dislocation density and higher tensile strength, therefore it could be used as toughening material in bioceramic.
发现国产紫胶中，紫胶桐酸C_（9、10）上的二个羟基处于交叉位，用现代光谱学手段证实了前人用化学方法推测的壳脑酸分子结构。
It was found that the two hydroxyl groups on C9,10 of aleuritic acid were in cross position. The molecular structure of shellolic acid was confirmed by modern spectrometry.
此外还检出了一整套直链一元仲醇同系物，其碳数从10至33，而羟基可在任何理论上可能的碳位上。
Straight chain alcohols range from 10 to 33 with the hydroxyl group at every theoretically possible positions.
通过对上述黄酮类化合物的构-效关系进行初步分析认为其6、8位的羟基对其活性具有重要意义。
Preliminary structure-activity analysis indicated that the existence of hydroxyl at both 6 and 8 position are imperative for the activity of flavonoid compounds.
反应机理推测为丝、苏氨酸的侧链基团羟基在咪唑的存在下亲核进攻磷原子形成五配位中间体。
Only N-phosphoryl serine and threonine methyl esters were catalyzed by imidazole, A new type of pentacoordinate phosphorus intermediate was proposed.
目的改进雌激素类化合物3位酚羟基的甲醚化工艺。
OBJECTIVE To improve the preparation of estrogen 3-methyl ether.
羟基处于醛基邻位和对位的苯甲醛与几种苯乙酮衍生物的缩合，多数没有得到预期的产物，或收率极低；苯乙酮环上的羟基对缩合反应影响很大，羟基越多，缩合越困难。
The groups in ring of benzaldehydes, no matter they are electron withdrowing or electron donating except of hydroxy, do not seem to have much effect on the yield.
而羧基邻位有酚羟基存在时，则配体以双齿形式与钛配位形成二茂钛六元环状化合物。
And if there is a hydroxyl in ortho position of carboxyl, the oxygen of hydroxyl and carboxyl in ligand are bound to ti to form hexatomic cyclic compound.
综述了在甾体化合物11 -位引入羟基的各种化学合成方法，主要包括酮基还原法、上脱卤素法、硼烷双氧水法、过氧化-还原法等。
Introduction of 11-hydroxy group into steroids by chemical methods, such as keto-reduction, halogenation-dehalogenation, borane-hydrogen peroxide and peroxidation-reduction are reviewed.
结论喜树碱A环的9，10位增加一个“1，4 氧嗪2 酮”六元环后，其抗肿瘤活性要比喜树碱或10 羟基喜树碱的活性降低。
Conclusion The modification of a 1,4-oxazine-2-one ring fused with positions 9 and 10 of A-ring will reduce the antitumor activity of camptothecins.
结论喜树碱A环的9，10位增加一个“1，4 氧嗪2 酮”六元环后，其抗肿瘤活性要比喜树碱或10 羟基喜树碱的活性降低。
Conclusion The modification of a 1,4-oxazine-2-one ring fused with positions 9 and 10 of A-ring will reduce the antitumor activity of camptothecins.
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