乙酰乙酸乙酯

Thus, 3 mol of Ethyl acetoacetate were treated with 2 mol of formaldehyde to yield 80% of I.

用2摩尔的甲醛处理3摩尔的乙酰乙酸乙酯可得到80%的I。

The synthesis of fructone from ethyl acetoacetate and ethylene glycol using sulfonated activated carbon as solid acid catalyst was investigated.

以活性炭磺化制得新型固体磺酸磺化炭为催化剂，对乙酰乙酸乙酯和乙二醇合成苹果酯的催化工艺进行了系统研究。

Various reaction parameters such as ratio of ethyl acetoacetate to ethylene glycol,catalyst amount,reaction time and water-carrying reagent amount were studied.

讨论了酯醇比、催化剂用量、反应时间、带水剂用量对酯化率的影响。最佳反应条件为：n：n=1：1.8，催化剂用量为乙酰乙酸乙酯质量的2%，带水剂用量为20mL，反应时间3h。

_6P_2W_(17)VO_(62) catalyst was prepared and characterized by FTIR,and synthesis of fraistone over as-synthesized catalyst from ethyl acetoacetate and 1,2-propylene glycol was investigated.

制备了Dawson型磷钨钒酸铵催化剂，用FT-IR分析方法对催化剂进行了结构表征，并以乙酰乙酸乙酯与1，2-丙二醇为原料催化合成了苹果酯-B。

Supported 12-Phosphotungstic Acid and Its Salts as Catalysts for the Synthesis of Fructone and Fructone-B;2. Their catalytic activities were measured by synthesis of fructone-B from ethyl acetoacetate and 1,2-propanediol.

制备了一系列以脱铝超稳Y沸石为载体的磷钨酸及其铯盐催化剂，考察了催化剂在以乙酰乙酸乙酯和1，2-丙二醇为原料催化合成草莓酯反应过程中的性能。

This thesis consists of four chapters:Chapter 1: Michael addition of chalcones with active methylene compounds such as diethyl malonate, ethyl acetoacetate and nitromethane catalyzed by potassium hydroxide in anhydrous ethanol results Michael adducts in 72-98% yield under ultrasound irradiation in 25-150min.

第一章：研究了超声辐射下，氢氧化钾催化的查耳酮与活泼亚甲基化合物如丙二酸二乙酯、乙酰乙酸乙酯和硝基甲烷的迈克尔反应。

Optically active ethyl-3-hydroxybutyrate,a useful chiral synthon,was prepared by stereoselective reduction of ethyl acetoacetate of the bread yeast in organic solvent.

利用面包酵母在非水相中不对称还原乙酰乙酸乙酯，制备了光学活性的手性化合物S-3-羟基丁酸乙酯。

Could keep above 95% in the fixed beds. In order to achieve high stereo-selectivity with yeast, ethyl acetoacetate was used as the model substrate,and a novel approach was proposed to selectively inhibit R-enzymes in yeast before reaction.

以乙酰乙酸乙酯为模型底物，以丙烯酸、乙醚、二甲基亚砜、丙烯酰胺、正己烷等有机溶剂选择性地抑制酵母中R型酶，提高反应立体选择性。

Methyl-l, 3-oxazine-2,4-dione are prepared from ethyl acetoacetate and ethyl carbamate at 140 for 6h, catalysted by zinc acetate, giving to 48.8% yields which is 33% more than the literature value.

选用醋酸锌作催化剂，使乙酰乙酸乙酯与氨基甲酸酯在140℃反应6h，合成6-甲基-1，3-噁嗪-2，4-二酮，产率达48.8％，较文献报道值高出了33％。

The asymmetric reduction of prochiral P-oxo ester, aromatic ketone and aliphatic ketone to its corresponding chiral alcohol by yeast cells were studied respectively in this work when ethyl 4-chloro-3-oxobutyrate, acetophenone and 2-octanone were as the model substrates.

本文以4-氯乙酰乙酸乙酯、苯乙酮和2-辛酮分别为β-羰基酯、芳香酮和脂肪酮的模型底物，研究了利用活性酵母细胞催化这三类前手性酮不对称还原合成相应手性醇的反应特性。

I didn't watch TV last night, because it .

昨晚我没有看电视，因为电视机坏了。

Since this year, in a lot of villages of Beijing, TV of elevator liquid crystal was removed.

今年以来，在北京的很多小区里，电梯液晶电视被撤了下来。