烯酮

Theoretical investigation of the solvent effects on the mechanism of the reaction of pentafulvenone with hydrocyanic acid to produce the main product of acid of type b was carried out at B3LYP/6-311+G(superscript **) level via the conductor-like polarizable continuum model.

在B3LYP/6-311+G计算水平上，采用导体极化连续模型研究了溶剂化效应对6-亚甲基环戊二烯酮与HCN反应生成主要产物b类酸的反应机理的影响。

In this reaction, the first example of 1,3-addition to ketene was observed.

研究中，我们首次观察到了对烯酮的1，3-加成反应。

First, a series ofα-oxo ketene dithioacetals were preparated on the basis of our recent work.

具体研究如下：1。在十分温和的条件下，合成了一系列α-羰基二硫缩烯酮类化合物。2。

Therefore it is very important to explore the feadibility of clean synthesis lf complex compounds from a-oxo ketene dithioacetals

因此，以a-羰基二硫缩烯酮类化合物为合成子，探索复杂化合物的绿色合成方法将具有重要意义

Oxo ketene dithioacetals are a kind of versatile intermediates in organicsynthesis. It can be widely used in forming aromatic and heterocyclic compounds.

α-羰基二硫缩烯酮类化合物是一类重要的有机合成中间体，广泛应用于芳环和杂环化合物的合成中。

In the meantime, we proposed a mechanism for this catalytic reaction. According to the possible formation of intermediate B, we designed a disubstituted ketene of more function to re-capture the zwitterion.

在同位素标记基础上，我们推测了这个N-甲基咪唑催化的二组分反应可能的机理，并根据此机理设计用一个二取代的烯酮来捕捉N-甲基咪唑和DMAD形成的两性离子。

The zwitterion derived from the addition of N-methylimidazole to DMAD was investigated and intercepted by a ketene.

我们用烯酮来捕捉N-甲基咪唑与活泼炔DMAD形成的两性离子。

Hydroxyl ketene dithioacetals were treated under diversely catalyzed conditions, and a wide range of significant compounds and synthetic precursors thus were obtained.

羟基二硫缩烯酮类化合物可以通过各种不同的反应条件进行多种转化，能够获得许多有意义的化合物和合成潜体。

Besides, The reaction of aldehydes with dithioacetate enethiolates followed by alkylation effectively gives α-hydroxyl ketene dithioacetals.

此外，用醛与硫代羧酸硫酯反应再通过烷基化也可以有效地获得α-羟基二硫缩烯酮类化合物。

Second, we investigated the aldol reactions of the specialα-oxo ketene dithioacetals with aromatic aldehydes under the mild conditions in good yields.

在温和的条件(室温、30℃)下，高产率地实现了α-羰基二硫缩烯酮与芳香醛的缩合反应。3。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。