环烯

It is found that the stereochemistry of the reactions of telluronium allylide,crotonylide and trimethylsilyallylide with α,β-unsaturated esters and amides can be tuned by thechoice of reaction conditions.

利用反应条件的变化首次实现了烯丙基、巴豆基、含硅烯丙基碲叶立德与α，β-不饱和酯、酰胺进行环丙烷反应的立体化学调控，能高立体选择性地、高效率地合成两种不同几何异构体中的一个。

Part Ⅱ: The evelopropanation reactions of both semi-stabilized telluronium and arsoniumylides with α,β--unsaturated ketones proceed smoothly.

第二部分：烯丙基、巴豆基、三甲基硅基烯丙基、肉桂基、苄基碲、胂两种叶立德与α，β-不饱和酮均可以成功地进行环丙烷化反应，并且表现出不同的立体选择性。

The change for substitute group on chlorin ring of chlorophyll-a derivative and the effect on their visible spectra is discussed and summarized according to relation of electron effect and substituted position of different groups with conjugated region.

根据不同取代基的电子效应、取代位置与分子共轭区域的联系，提出二氮杂轮烯和四氮杂轮烯组成的非等原子芳香体系结构，总结了卟吩大环上的化学结构变化对其可见光谱的影响。

We conclude that PGI2 is the major AA metabolite in lean coronaries, and AA-mediated BK channel actiation is impaired in ZDF coronaries due to reduced PGIS actiity.

由此，我们得出结论：在瘦鼠的冠脉中，前列环素是花生四烯酸主要的代谢产物，而在zdf老鼠中，由于前列腺素合酶的活性的下降，花生四烯酸介导的BK通道的活化作用被削弱了。

The results showed that Kaidimycin was chemically neutral, macrocylic polylactones, stable and liable to dissolve into water and pyridine, slight to dissolve into methanol, ethanol and N-butanol, difficult to dissolve into ethyl acetate, acetone, benzene and chloroform. Chemical reaction of functional group of Kaidimycin showed that it had glycoside, amino acid and aldehyde, no reducing sugar, polypeptide and phenol.

凯地菌素属中等极性的、中性抗生素，极性纸层析结果与多烯类抗生素的纸层析结果相似：易溶于水、吡啶，微溶于甲醇、乙醇、正丁醇，不溶于乙酸乙酯、丙酮、苯、三氯化碳；对高温、光照和紫外处理有很好的稳定性；官能团反应试验结果发现，凯地菌素可能含有糖苷键、氨基酸伯氨基和醛基，不含有还原糖、多肽和酚基，高锰酸钾、浓硫酸反应与多烯大环内酯类抗生素的特性相似；并且依据纯品，采用生物法和分光光度法对摇床发酵液进行了效价的测定。

This novel reagent was treated with LDA to produce polystyrene-supported a-seleno carbanions, which reacted with alkyl halides and epoxides, followed by stereospecific selenoxide syn-elimination to give olefins and allylic alcohols respectively.

它与LDA反应形成α—硒基稳定的碳负离子，再与卤代烃或环氧化合物发生α—烷基化反应，烷基化后的树脂可以在30%的双氧水中进行氧化-消除，以良好产率和较高纯度合成了取代烯烃或烯丙基醇。

Intend to use the most advanced technologies in building the 20,000 t/y propylene oxide plant, hydrogen peroxide and propylene as raw materials. Process control using phase transfer catalyst reaction of propylene oxide technology, non-polluting, non-joint products.

拟采用国内先进技术建设2万吨/年环氧丙烷生产装置，以双氧水和丙烯为主要原料，生产工艺采用反应控制相转移催化丙烯氧化技术，无污染、无联产品。

Isoquinuclidines are structural elements of numerous alkaloids and can be prepared from the reaction of imines with cyclohexenone.

isoquinuclidines结构性因素众多生物碱可制备烯合成环己烯酮与亚胺反应。

Feeding for 24h by third instar larvae of the maize stalk borer induced farnesyl pyrophosphate synthase gene expressing, but had no effect on expression of AOC, BX9, PAL and PR2a genes and DIMBOA content.

3玉米螟3龄幼虫处理24h能诱导玉米根中法呢烯基焦磷酸合成酶基因表达，但不能诱导丙二烯氧化物环化酶、β－1，3葡聚糖酶基因（PR2a）、糖基转移酶（BX9）、苯丙氨酸转氨酶基因表达，同时对第二叶和根中丁布含量无显著影响，使第二叶对羟基苯甲酸及第三叶丁布、对羟基苯甲酸、香草酸含量显著降低。

The epoxidation of α-pinene and β-pinene by 50% hydrogen peroxide and a small amount of sodium tungstate, in the presence of quaternary ammonium salt A-1 as a phase transfer catalyst, is carried out.

摘 要：采用季铵盐A-1作相转移催化剂，质量分数为50%的H2O2作氧化剂，三氯甲烷作溶剂，在加入少量钨酸钠的条件下，实现了α-蒎烯和β-蒎烯的环氧化反应。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失