缩酮

Catalytic activity of phosphotungstic acid on synthesizing butanone 1,2-propanediol ketal was discussed,the factors influencing the synthesis were discussed and the best conditions were found out.

探讨了磷钨酸对丁酮1，2 丙二醇缩酮合成反应的催化活性，研究了酮醇摩尔比、催化剂用量、反应时间等因素对产品收率的影响。

Sodium bisulfate is an excellent catalyst for synthesizing butanone 1,2-propan.

以一水合硫酸氢钠为多相催化剂，由丁酮和1，2-丙二醇反应合成了丁酮1，2-丙二醇缩酮。

We also found for the first time that the reaction between ketone and alcohol to ketal was catalyzed by benzamide and their derivatives, and the related mechanism is proposed. Furthermore, under the same irradiation condition, the photo-reaction of succimide with alcohol as well as the photolysis of benzene sulfonamide was also found and studied.

并首次发现在紫外光激发下，苯甲酰胺对酮和醇生成缩酮的反应有一定的催化作用，进而对一系列芳酰胺类化合物作了对比实验，发现芳酰胺类化合物均能对缩酮的生成有催化作用，并对芳酰胺的作用机理进行了初步探讨。

Glucose an aldohexose, exists as D and L forms. The furthest asymmetric carbon from the aldehyde group is C-5. D-glucose is called D because the configuration of the atoms bonded to C-5 is the same as for D-gly- ceraldehyde. Similarly D-fructose﹙a ketohexose﹚ is designated D because the configuration

环状结构：醛基或酮基跟一个羟基反应共价闭合，形式上一个糖的醛基和羟基反应生成了一个半缩醛，而一个酮基与一个羟基反应生成一个半缩酮，在同一分子内这个反应能进行，单糖的开链式形成了糖环，葡萄糖环形成一个六碳环。

Catalytic synthesis of ketal by urushiol-formaldehyde neodymium polymer from cyclohexanone and ethanediol was studied.

以环己酮和乙二醇为原料，漆酚缩甲醛钕聚合物为催化剂合成了环己酮乙二醇缩酮。

H3PW6Mo6O40/TiO2 was used as the catalyst in the synthesis of cyclohexanone ethylene ketal. The effects of varying the n:n ratio, catalyst dosage and reaction time on the yield were investigated.

以H3PW6Mo6O40/TiO2为催化剂，对以环己酮与乙二醇为原料合成环己酮乙二醇缩酮的反应条件进行了研究，较系统地研究了酮醇物质的量比、催化剂用量、反应时间对收率的影响。

Under these conditions, the yield of cyclohexanone glycol ketal could be reach 90.4%, indicating that rare earth composite solid superacid SO4(superscript 2-)/ZrO2(superscript 3+) is a good catalyst for the synthesis of cyclohexanone glycol ketal.

在此条件下，缩酮收率可达90.4%，说明稀土复合固体超强酸SO4(上标 2-)/ZrO2/Gd(上标 3+)是一种合成环己酮乙二醇缩酮的优良催化剂。

Cyclohexanone ethylene ketal was synthesized from cyclohexanone and glycol in the presence of H3PW12O40/MCM-48. The factors influencing the synthesis of molar ratio of glycol to cyclohexanone, the quantity of catalyst and the reaction time were discussed and the best conditions were found out.

报道了以分子筛MCM-48负载磷钨酸(H3PW12O40/MCM-48)为催化剂，通过环己酮和乙二醇反应合成了环己嗣乙二醇缩酮，探讨了H3PW12O40/MCM-48对缩峒反应的催化活性，较系统地研究了酗醇物质的量比，催化剂用量，反应时间诸因素对产品收率的影响。

It is suggested that the scission is preceded by an aldol condensation, followed by a phenolic hydroxyl participation with scission of the C---C in the β-hydroxy-ketone formed.

经推论这一断键反应首先是发生羟醛缩合，继以在酚羟基参与下引发烷羰C－C键断裂的；还应指出，也是由于对位羟基的参与，这些烷基对羟苯基酮不形成它们的乙醇缩酮。

The homocamptothecins with different substituted group in ring A and ring B can be obtained by the Friedlander condensation of the ring CDE with the acetals or 2-aminophenyl ketones.

以不同的缩醛与CDE环经Friedlander反应，可以得到A环上不同取代的高喜树碱类化合物，以缩酮或芳香酮反应，则可得到同时在A、B环取代的高喜树碱。

I am accused of being overreligious," she said in her quiet, frank manner,"but that does not prevent me thinking the children very cruel who obstinately commit such suicide.""

客人们在卡罗利娜·埃凯家里，举止就文雅一些，因为卡罗利娜的母亲治家很严厉。

Designed by French fashion house Herm è s, this elegant uniform was manufactured in our home, Hong Kong, and was the first without a hat.

由著名品牌 Herm è s 设计，这件高贵的制服是香港本土制造，是我们第一套不配帽子的制服。