乙酰乙酸

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。

L-Phenyl-3-methyl-5-pyrazoIone was synthesized by the reaction of ethyl acetoacetate and phenyl hydrazine in ethanol.

在无水乙醇的存在下，乙酰乙酸乙酯和苯肼为原料合成标题化合物。

Dehydroacetic acid was synthesized from acetacetic ether, and the influent factors of productive rate were investigated.

研究了以乙酰乙酸乙酯为原料合成脱氢醋酸过程中，催化剂的种类、用量以及反应时间对产物得率的影响。

Their specific surface area and acid strength were measured, and their catalyt and SBA-15 were ic performance was evaluated in the synthesis of fructone by acetalization of ethyl acetoacetate with ethylene glycol.

用浸渍法制备了一系列负载型磷钨酸及其铯盐催化剂，载体包括超稳Y沸石、脱铝超稳Y沸石、SiO2和SBA-15，测定了催化剂的比表面积和酸强度，并在乙酰乙酸乙酯与乙二醇液相缩合制取苹果酯反应中考察了催化剂的性能。

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。

The strongly acidic cation exchange resin catalyzed synthesis of fructone-B by the reaction of ethyl acetoacetate and 1,2-propanediol was studied.

以硫酸高铈铵为催化剂，通过乙酰乙酸乙酯分别与乙二醇和1，2-丙二醇反应合成了苹果酯-A和苹果酯-B，研究了催化剂等有关因素对产品收率的影响。

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。

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。