苄基酒石酸甲乙酯的立体选样性合成

本文报道了赤式苄基酒石酸甲乙酯(3)的立体选择性合成,其^1H核磁共振谱,红外光谱和质谱与预期的结构一致.这个方法对合成其它具有赤式酒石酸结构的天然产物有一定的参考价值.     

一个制备手性烯醇硅醚的新方法

本文合成了8个手性烯醇硅醚, 其中5个为新化合物, 其结构为IR, 1HNMR和MS所证实。     

3-亚甲基异吲哚酮的合成新方法

亚甲基异吲哚酮衍生物2是一类重要的药物合成中间体, 近来又被用作新型有机金属染料合成的配体。文献报道化合物2的主要合成方法是采用苯基锂衍生物的分子内反应, 或以有机钛为主要原料合成目标产物, 但以上方法原料难得, 反应条件苛刻, 产率不理想, 难以大规模合成。我们首次发现以苯基环缩醛为原料一步法合成亚甲基异吲哚酮2的新方法, 原料易得, 条件温和, 操作简便, 产率良好, 为苯甲醛作起始原料合成化合物2提供了一条新途径。     

百部生物碱的化学研究 I. 细花百部新生物碱

从海南岛产野生百部, 细花百部(Stemona parviflora Wright C.H.)的根部又分得三个新生物碱, 分别命名为细化百部酰胺(parvistemoamide)(1), 细花百部次碱(parvistemolone)(2)和脱氢细花百部碱(didehydroparvistemonine)(3)。经IR, MS,^1H和^1^3C NMR、NOE差谱, 2D-同核及异核相关谱等技术推定了结构。同时归属了它们的^1H和^1^3C NMR信号。     

微波促进的1,3-偶极环加成4β-1,2,3-三唑鬼臼毒素的合成

在微波作用的无溶剂条件下，由4β-叠鬼臼毒素与炔烃反应，合成了8个含有 1,2,3-三唑的鬼臼毒素衍生物，并用IR, ~1H NMR, MS确定了这些化合物的结构。 该反应操作简单，产率较高，副产物少，同时具有原子经济性。     

百部生物碱的化学研究 I. 细花百部新生物碱

从海南岛产野生百部, 细花百部(Stemona parviflora Wright C.H.)的根部又分得三个新生物碱, 分别命名为细化百部酰胺(parvistemoamide)(1), 细花百部次碱(parvistemolone)(2)和脱氢细花百部碱(didehydroparvistemonine)(3)。经IR, MS,^1H和^1^3C NMR、NOE差谱, 2D-同核及异核相关谱等技术推定了结构。同时归属了它们的^1H和^1^3C NMR信号。     

双(三苄基锡)二元羧酸酯的合成及生物活性

以三苄基氧化锡和相应的二元羧酸反应,合成了14种新的双(三苄基锡)二元羧酸酯。利用元素分析、IR、^1HNMR和MS表征了这些化合物的结构。生物活性测试表明,该类化合物具有较好的杀菌活性。     

冠醚化合物的合成 X: 双酰胺双-(3'正十五烷基-苯并-15-冠-5)的合成

本文设计并合成了3'-正十五烷基-5'-硝基-苯并-15-冠-5(1)、3-正十五烷基-5'-氨基-苯并-15-冠-5(2)和十种双酰胺双(3'-正十五烷基-苯并-15-冠-5)(3a-3j), 其合成路线如下.     

3-丁烯酮-吲哚衍生物的合成

吲哚类化合物广泛存在于植物界中, 且具有多种生理活性。其中, 月橘烯碱具有抗生育活性。本文以合成月橘烯碱的中间体3-(1-丁烯酮-3)吲哚为起始物, 并设计了10个与其结构类似的单吲哚化合物, 并做了小鼠的药理实验。     

土槿皮新二萜成分的研究 IV: 土槿丁酸和土槿戊酸的分离和结构测定

从土槿皮(Pseudolarix kaempferi, Gord.)中分离到两个新二萜酸, 命名为土槿丁酸(1)和土槿戊酸(2), 经理化性质和对它们的IR、^1H NMR、^1^3C NMR、MS数据的分析, 鉴定1为 18-羟-对映-贝壳杉-15-烯-17-羧酸; 2为对映-贝壳杉-15-烯-17, 18-二羧酸. 1的结构经X衍射得到了证实.     

Carbamoylimidazolium salts as diversification reagents: an application to the synthesis of tertiary amides from carboxylic acids

An efficient method for the preparation of tertiary amides from carbamoylimidazolium salts and carboxylic acids is described. The transformation occurs at room temperature and under relatively mild conditions. The carbamoylimidazolium salts are obtained from the reaction of secondary amines with N,N′-carbonyldiimidazole, followed by methylation with methyl iodide. The utility of this reaction was demonstrated in the formation of Weinreb amides and in a short synthesis of fused bicyclic amides. The introduction of this reaction now permits carbamoylimidazolium salts to be utilized in the formation of tertiary amides, ureas, carbamates and thiocarbamates under a single set of conditions.     

A novel method for the one-pot conversion of carboxylic acids to N,N-dimethylamides

A simple, efficient, and new method has been developed for the preparation of N,N-dimethylamides from carboxylic acids. As described below, treatment of a variety of aromatic carboxylic acids with N,N-dimethylsulfamoyl imidazole or N,N-dimethylsulfamoyl chloride in the presence of a mixture of methanesulfonic acid/phosphorus pentoxide (2:1, v/w) proceeded effectively to afford the corresponding N,N-dimethylamides in moderate to good yields. This method is easy, rapid, and good yielding for the synthesis of N,N-dimethylamides from carboxylic acids.     

一种由多氟碘代烷合成多氟羧酸的新方法

本文报道了一种新的合成多氟羧酸的方法:即在银(I)离子存在下,甲酸钠与多氟烷基碘代烷反应的结果。     

One-pot synthesis of ketones from carboxylic acids and grignard reagents using N,N-Diphenyl-p-methoxyphenylchloromethyleniminium chloride

N,N-Diphenyl-p-methoxyphenylchloromethyleniminium chloride is found to be an effective condensation reagent of carboxylic acids and Grignard reagents under mild conditions to afford the corresponding ketones in high yields.     

Thioimides: new reagents for effective synthesis of thiolesters from carboxylic acids

Thioimides and carboxylic acids are used as the precursors for the convenient synthesis of thiolesters in the phosphine mediated process. Cyclic and acyclic thioimides show equal efficiency, furnishing the desired thiolesters in good to excellent yields. The general, highly efficient transformation tolerates various functional groups and the resulting thiolesters are obtained in high purity after a simple separation. The reaction scope has been demonstrated on the preparation of several highly functionalized target molecules.     

One-pot Vilsmeier reagent-mediated multicomponent reaction: A direct synthesis of oxazolones and Erlenmeyer azlactones from carboxylic acids

N-Acylation of glycine with carboxylic acids was carried out by using the Vilsmeier reagent. The resulting N-acyl-α-amino acids were subsequently cyclodehydrated into oxazol-5-ones via the Vilsmeier reagent. Finally, treatment of oxazol-5-ones with aldehydes in the presence of the Vilsmeier reagent delivered Erlenmeyer azlactones. By combining these steps, using the Vilsmeier reagent allowed direct one-pot conversion of carboxylic acids into oxazol-5-ones and direct one-pot conversion of carboxylic acids into Erlenmeyer azlactones in the presence of aldehydes. These Vilsmeier reagent-mediated multicomponent reactions proceeded smoothly in reasonable chemical yields at room temperature. The chemical structure of the title compounds was confirmed by spectral data.     

A novel system for the synthesis of nitriles from carboxylic acids

A simple, mild and high yielding method for the conversion of various carboxylic acids to nitriles has been developed using diphosphorus tetraiodide in combination with ammonium carbonate at room temperature.     

A new direct synthesis of cinnamic acids from aromatic aldehydes and aliphatic carboxylic acids in the presence of sodium borohydride

Cinnamic acids have been prepared in 59-86% yields by a new direct synthesis from aromatic aldehydes and aliphatic carboxylic acids in the presence of sodium borohydride and N-methyl-2-pyrrolidinone (NMP) as solvent, at reflux (185-190°C), for 9-12 hours. Without sodium borohydride, this reaction is not possible.