三碘化钐促进的α, α'-二(取代亚苄基)环戊酮的简便合成

在SmI3作用下和中性室温的条件下, 环戊酮能与醛缩合, 得到几乎定量产率的α, α'-二亚苄基环戊酮; 但对环己酮, 产率仅在20%左右。     

固体超强碱催化环戊酮的Self-Aldol Condensation反应研究

2-环亚戊基环戊酮是一种重要的香料中间体,本文以环戊酮为原料,固体超强碱为催化剂,分别选用环己烷、苯、石油醚为带水剂,通过Aldol自缩合反应合成了环戊酮的二聚体2-环亚戊基环戊酮.考察了催化剂用量、带水剂种类、反应时间对环戊酮二聚体2-环亚戊基环戊酮收率的影响,最终确定最佳实验方案:环己烷为带水剂,催化剂用量为环戊酮...     

固体碱催化环戊酮和碳酸二甲酯合成己二酸二甲酯

以固体酸碱为催化剂,研究了碳酸二甲酯与环戊酮合成己二酸二甲酯的反应,并考察了反应温度、反应时间、催化剂用量和原料摩尔配比等因素对反应结果的影响．结果表明,固体酸催化剂不利于己二酸二甲酯的生成,而具有中强碱位的MgO对反应具有较好的催化性能．当以MgO为催化剂,在反应温度为260℃,反应时间5h,催化剂用量为反应物质量的1．5％,原料摩尔配比为环戊酮／DMC=1／4的最佳条件下,环戊酮的转化率和己二酸二甲酯的选择性分别达到85．5％和50．9％．同时,反应的主要副产物为环戊酮自身缩合的产物（2．环戊烯基环戊酮）以及环戊酮的甲基化产物（2-甲基环戊酮、2-甲基己二酸二甲酯）等．另外,反应是通过固体碱活化环戊酮的α-H进行,而2-甲氧基羰基环戊酮是生成己二酸二甲酯的中间体．     

2－戊基环戊－2－烯酮的合成研究

以环戊酮、正戊醛为原料，采用相转移催化技术进行羟醛缩合，经脱水得到２－戊叉环戊酮，再经异构化，合成了２－戊基环戊－２－烯酮。文章对相转移催化合成２－戊叉环戊酮及其异构化的条件进行了研究。     

不动杆菌静息细胞催化拆分外消旋环戊酮醇乙酸酯反应条件的优化

 考察了反应条件对不动杆菌Acinetobactersp．YQ231催化外消旋环戊酮醇乙酸酯对映选择性水解的反应速度和对映选择性的影响．确定的最佳酶反应条件为pH8．0，温度50℃．不同乳化剂对对映选择性的影响不同，以壬基酚聚氧乙烯醚的效果最好，当其加入量为15g／L时，反应的对映选择性最高．产物环戊酮醇对酶活性有显著的抑制作用．细胞中的酯酶优先水解（R）－环戊酮醇乙酸酯，生成（R）－环戊酮醇，在底物浓度为250mmol／L时，对映体比率（E值）可达50．     

2,3-环戊烯并吡啶的多相催化合成

以丙烯醛和环戊酮为原料,用固定床多相催化法合成了2,3-环戊烯并吡啶,收率65%(以环戊酮质量计算),含量高于50%.     

三碘化钐促进的α,α′-二(取代亚苄基)环戊酮的简便合成

在SmI_3作用下和中性室温的条件下,环戊酮能与醛缩合,得到几乎定量产率的α,α＇-二亚苄基环戊酮;但对环已酮,产率仅在20％左右。     

Ni-Co/TiO2对糠醛制环戊酮、环戊醇的催化性能

以TiO2为载体负载双金属活性组分Ni-Co,采用浸渍法制备催化剂,用于糠醛催化加氢生成环戊酮和环戊醇的反应,并探讨了Ni-Co负载量、反应时间、反应温度、反应压力对其他产物的影响。通过XRD、BET、H2-TPR、SEM等表征方法对催化剂的构成及反应机理进行了讨论。结果表明,分别以一定比例负载金属活性组分制备的Ni-Co/TiO2和Co/TiO2催化剂,在最佳反应条件下环戊酮和环戊醇的生成率达到最高值,分别为53.4%和17.1%。     

2-取代-环戊烯酮及其衍生物的简易合成

本文报道以2-氯环戊酮的加成重排反应合成2-取代环戊酮。如再引入硫硫双键,则可合成2-取代环戊烯酮。取代环戊酮和取代环戊烯酮是合成药物和合成香料的重要中间体。     

环戊叉基环戊酮的烷基化反应研究

研究了环戊叉基环戊酮与不同类型烷化剂的反应规律；讨论了不同催化剂对烷基化反应的催化性能，发现ＮａＮＨ２和ＮａＨ具有较好的催化作用；讨论了烷基化产物的结构，证实了烷基化反应发生在羰基的α双键碳原子上。     

Aqueous-phase catalytic hydrogenation of furfural to cyclopentanol over Cu-Mg-Al hydrotalcites derived catalysts: Model reaction for upgrading of bio-oil

A series of Cu-Mg-Al hydrotalcites derived oxides with a (Cu+Mg)/Al mole ratio of 3 and varied Cu/Mg mole ratio (from 0.07 to 0.30) were prepared by co-precipitation and calcination methods, then they were introduced to the hydrogenation of furfural in aqueous-phase. Effects of Cu/Mg mole ratio, reaction temperature, initial hydrogen pressure, reaction time and catalyst amount on the conversion rate of furfural as well as the selectivity toward desired product cyclopentanol were systematically investigated. The conversion of furfural over calcined hydrotalcite catalyst with a Cu/Mg mole ratio of 0.2 was up to 98.5% when the reaction was carried out under 140 °C and the initial hydrogen pressure of 4 MPa for 10 h, while the selectivity toward cyclopentanol was up to 94.8%. The catalysts were characterized by XRD and SEM. XRD diffraction of all the samples showed characteristic pattern of hydrotalcite with varied peak intensity as a result of different Cu content. The catalytic activity was improved gradually with the increase of Cu component in the hydrotalcite.     

简法合成二氢茉莉酮酸甲酯和二氢新茉莉酮酸甲酯

以环戊二烯为原料,先合成了环戊-2-烯酮(1),(1)经过Michael加成反应得到3-酮-环戊基乙酸甲酯(4)。再经过Aldol缩合反应和催化氢化,得到二氢茉莉酮酸甲酯和二氢新茉莉酮酸甲酯。     

Synthesis of dimethyl adipate from cyclopentanone and dimethyl carbonate over solid base catalysts

A facile route for the synthesis of dimethyl adipate (DAP) from cyclopentanone and dimethyl carbonate (DMC) in the presence of solid base catalysts has been developed.It was found that the intermediate carbomethoxycyclopentanone (CMCP) was produced from cyclopentanone with DMC in the first step,and then CMCP was further converted to DAP by reacting with a methoxide group.The role of the basic catalysts can be mainly ascribed to the activation of cyclopentanone via the abstraction of a proton in the α-position by base sites,and solid bases with moderate strength,such as MgO,favor the formation of DAP.     

Catalytic Ketonization over Oxide Catalysts, Part IV. Cycloketonization of Diethyl Hexanodiate

Activity of 20 wt.% MO₂/S catalysts, where M = Mn, Ce and Th, and S = Al₂O₃ or SiO₂, has been studied in cycloketonization of diethyl hexanodiate at the temperature range 573-698 K in a flow system. Only moderate yields of cyclopentanone (<35%) were achieved. The highest yields of ketone were obtained over MnO₂/Al₂O₃ and MnO₂/SiO₂ catalysts - 33 and 27%, respectively. ThO₂ containing catalysts were the most active, whereby ester transformations were detected below 573 K. In the presence of all catalysts the formation of the main product was accompanied by various amounts of 2-ethylcyclopentanone, cyclopent-2-en-1-one, cyclopentene, 2-cyclopentylidenecyclopentanone and numerous unidentified by-products.     

二氢茉莉酮酸甲酯的简便合成方法

本文报道二氢茉莉酮酸甲酯的简便合成方法。先由丁二酸和庚酰氯反应得到2-戊基-1,3-环戊二酮(1),再用甲醇醚化1,可得到2-戊基-3-甲氧基-环戊-2-烯酮(2)。2与丙二酸二甲酯反应生成(2-戊基-3-酮-1-环戊烯-)基乙酸甲酮(3)。最后,催化氢化3,便可得到二氢茉莉酮酸甲酯(4)。     

Unprecedented chemo-enzymatic synthesis of stereochemically pure 3-acetoxy-2-methyl-2-vinylcycloalkanones

A new approach to 3-acetoxy-2-methyl-2-vinylcyclohexanone and 3-acetoxy-2-methyl-2-vinylcyclopentanone in stereochemically pure state, by means of a combination of yeast-catalyzed reduction and subsequent radical β-fragmentation is described.     

Synthesis of 1,4-dimethylhydroazulene derivatives fromtrans-3-isopropenyl-2-(2-methoxycarbonylethyl)cyclopentanone

The title cyclopentane keto ester was used as the key compound in stereoselective syntheses of 1,4-dimethylhydroazulene derivatives which served as precursors for guaiane type sesquiterpenes.Deceased Nov., 1, 1992.Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 122–125, January, 1993.     

Liquid phase hydrogen transfer to cyclopentanone over MgO-I2 and MgO-RI catalysts

Instead of cyclopentanol, 2-cyclopentylidene-cyclopentanone is the main product of liquid phase hydrogen transfer from secondary alcohols to cyclopentanone in the presence of pure MgO [1]. In the present work it has been shown that a significant increase in the selectivity towards cyclopentanol has been observed for MgO treated with I₂ or alkyl iodides.