查询词典 ketal

Chemoselective protection of the saturated carbonyl as the ethylene ketal- 10 was achieved via the conditions of Demnitz et al.

化学选择性保护作为饱和羰乙烯酮-10经取得demnitz等条件。

Cyclohexanone glycol ketal was synthesis from cyclohexanone and ethylene glycol in the presence of a late-model catalyst, which was prepared with fly ash as raw material. The catalysts were characterized by means of XRD, TG and FTIR.

以粉煤灰为原料制备了一种新型的固体酸催化剂，用X射线衍射、热分析和红外光谱等手段表征了催化剂的物化性能。

The optimal conditions were found to be: n:n=1:1.5; mass fraction of catalyst to reactants, 1.0%; reaction time, 0.75 h and dried cyclohexane, 8 mL. Under these conditions, the yield of cyclohexanone ethylene ketal was 87.7%.

实验结果表明，在n∶n=1.0∶1.5、催化剂用量占反应物料总质量的1.0%、反应时间0.75 h的条件下，环己酮乙二醇缩酮的收率为87.7%。

Cyclohexanone ethylene ketal was synthesized using vitamin C as the catalyst by microwave irradiation solvent-free method.

以维生素C为催化剂，采用微波辐射无溶剂催化合成环己酮乙二醇缩酮，探索了不同反应条件对产率的影响。

Hβ zeolite ; seven-member-ring ketal ; 1; 4-butanediol ; synthesis ; catalyst

Hβ；七元环缩酮； 1； 4-丁二醇；环己酮；合成；催化剂

The optimum conditions are: molar ratio of glycol to cyclohexanone is 1.6:1, the quantity of catalyst is equal to 0.25% of feed stocks, and the reaction time is 40 mm. H3PW12O40/MCM-48 is an excellent catalyst for synthesizing cyclohexanone ethylene ketal and its yield can reach over 80.63%.

实验表明：H3PW12O40/MCM-48是合成环己酮乙二醇缩酮的良好催化剂，在n：n＝1：1.6，催化剂用量为反应物料总质量的0.25%，环己烷为带水剂，反应时间40min的优化条件下，环己酮乙二醇缩酮的收率可达80.63%。

A new phenomenon that ketal can be deprotected by strong base NaH wasfound.

在实验过程中首次发现在强碱氢化钠作用下，缩酮结构能脱去保护基而复原为酮基这一现象。

The effects of reaction time, mole ratio of reactants and amount of catalyst on yield of ketal were investigated by using the [SO3H-bPy] [H2PO4] ionic liquid as catalyst. Results show that the ionic liquid was an efficient catalyst for the ketalization with high conversion and selectivity in mild conditions.

以磺酸基功能化的吡啶磷酸类离子液体[SO3H-bPy][H2PO4]为催化剂，系统考察了反应时间、酮与醇的配比、催化剂的用量及催化剂重复使用、不同阴离子、阳离子等因素对反应的影响，优化了反应条件。

The results showed that molar ratio of cyclohexanone to ethylene glycol was 1∶1.4, the amount of catalyst was 2% cyclohexanone, amount of cyclohexane was 10 mL, the reaction time 2 h, the yield of cyclohexanone ethylene ketal reached 99.6% under the optimum condition.

通过正交实验得出了最佳反应条件：n∶n=1∶1.4、催化剂用量为环己酮质量的2%、带水剂环己烷用量10.0 mL、反应时间2 h，缩酮产率可达99.6%。

Catalytic Synthesis of Cyclohexanone 1, 2-Propylene Ketal by Chitosan Supported with Iodine

篇名 壳聚糖负载单质碘催化合成环己酮1， 2-丙二醇缩酮

Lugalbanda was a god and shepherd king of Uruk where he was worshipped for over a thousand years.

Lugalbanda 是神和被崇拜了一千年多 Uruk古埃及喜克索王朝国王。

I am coming just now,' and went on perfuming himself with Hunut, then he came and sat.

我来只是现在，'歼灭战perfuming自己与胡努特，那麼，他来到和SAT 。