Synthesis of Rigid Analogues of (D,L)-Arginine Methyl Ester with Antiarrhythmic Activity

The synthesis of the methyl esters of racemic trans and cis 4-guanidinocyclohexylglycine as rigid analogues of (D, L)-arginine methyl ester is described.     

High-Pressure Approach to the Synthesis of Optically Pure Methyl 4-Deoxyheptosides

Recently we have described¹ high pressure (4+2) cycloaddition of l-methoxybuta-1,3-diene (1)to 2,3-0-isopropylidene-D-glyceraldehyde (z), which gives rise to chiral cycloadducts 3 (Scheme). action was carried out under high-pressure conditions (22 kbar, 50°C. diethyl ether as solvent, 20 h, 80% yield)2 four diastereoisomeric adducts were formed in a ratio of 3a:3b:3c:3d=66:16:13:5. The reaction mixture was separated by column chromatography yielding two fractions which contained diastereoisomeric mixtures (3a+3b) and (3c+3d), respectively. Absolute configuration at the C-5 carbon atom in both mixtures was established by chemical correlation.' These results prompted us to use a mixture (3a+3b), being stereochemically pure at C-5 chiral center, in the synthesis of optically active methyl 4-deoxyheptosides (Scheme).     

Optically Pure Isoproterenol Analogues With Side Chains Containing an Amide Bond: Synthesis and biological properties

The isoproterenol analogues 4a and 4b , synthesized as mixtures of Diastereoisomers, were shown to possess very potent β-adrenoceptor agonistic activity. Therefore, the four possible diastereoisomers of 4a have been synthesized and tested for inotropic activity. The (6R, 2′R)-diastereoisomer turned out to be the most interesting one. Consequently, also (6R,2′R)- 4b has been prepared and tested. For the diastereoselective synthesis, three variants have been elaborated: (i) coupling of epoxides 12 with amines 27 (Scheme 6); (ii) coupling of the activated glycol 17 with the amine 22 (Scheme 8); (iii) diastereoselective hydrogenation of the amino ketone 31 (Scheme 7). Both (6R,2′R)- 4a and (6R,2′R)- 4b show long lasting positive inotropic activity after intravenous as well as oral administration and are at least three times as potent as rac-isoproterenol. In the anesthetized dog, a good separation of positive inotropic and positive chronotropic effects is observed. In conscious dogs, however, heart rate and contractile force increase to the same extent (possibly due to reflex tachycardia).     

Synthesis of Optically Pure Helicene Metallocenes

Two types of ruthenocenes and a ferrocene coordinated by rac ‐9H ‐cyclopenta[1,2‐c :4,3‐c ′]diphenanthrenyl anion(s), a [7]helicene with a cyclopentadienyl moiety at the center of its skeleton, were successfully synthesized: mono‐helicene ruthenocene 1 and its iron analogue 1_Fe with one [7]helicene ligand bound to the central metal, and bis‐helicene ruthenocene 2 with two [7]helicenes. Starting from a racemic mixture of the ligand precursor, rac ‐ 2 and meso ‐ 2 were obtained in a 7:3 ratio. Since the [7]helicene has a high racemization barrier, enantiomers of the complexes were isolated in their pure forms; they showed large optical rotations and intense circular dichroism (CD) responses.     

合成光学活性菊酸酯的方法

Ｌ－孟醇与过量外消旋菊酰氯反应表现出非对映异构体选择性,得到了光学活性菊酸的Ｌ－孟醇酯。由外消旋菊酸的Ｌ－孟醇酯经异构化反应也得到了光学活性菊酸的Ｌ－孟醇酯。     

新的溶致液晶性高分子——N-马来酰化壳聚糖的合成与表征

新的溶致液晶性高分子——Ｎ┐马来酰化壳聚糖的合成与表征董炎明李志强（厦门大学化学系福建厦门３６１００５）壳聚糖（（１，４）－２－氨基－２－脱氧－β－Ｄ－葡聚糖）是甲壳素经脱乙酰化得到的一种生物高分子。它的原料是海产品加工厂的废料，因而来源十分丰富，作...     

"一锅法"合成戊二烯甲酯

以丙烯醛和丙二酸为原料,经缩合反应制得戊二烯酸,产率52．2％。采用“一锅法”合成了戊二烯酸甲酯,产率52．8％。其结构经^1H NMR和IR确证。     

苏型-N-苯甲酰基-3-苯基异丝氨酸甲酯的合成

紫杉醇;苏型-N-苯甲酰基-3-苯基异丝氨酸甲酯的合成     

Synthesis of 9-Deoxynanaomycin a Methyl Ester1

The tricyclic intermediate 6 prepared in three steps from 1,4-dimethoxynaphthalene was utilized in preparing alkene 7. Cleavage of the double bond of 7 furnished the keto aldehyde 9 which was transformed to the unsaturated ester 13. The ester 13 on heating with KOH-MeOH furnished the acid 14a whose methyl ester was oxidised to 9-deoxynanaomycin A methyl ester (2).     

Synthesis of Optically Active Methyl 12-Oxo-9,10-epoxyoctadecanoate

The procedure for synthesizing optically active methyl 12-oxo-9,10-epoxyoctadecanoate (enantio- meric purity 90%) was developed, starting from ricinolic acid methyl ester.     

含芴基的旋光末端环氧和环硫化合物的合成

先利用芴与乙醇钠反应或者三苯甲醇与浓磷酸反应, 制备相应的9-烃基芴, 再利用正丁基锂与9-烃基芴反应得到相应的锂盐, 然后在－70 ℃下滴加旋光的环氧氯丙烷, 滴加完毕后在室温搅拌几小时, 得到光学纯的含芴基取代末端环氧化合物, 它们的ee值均大于98%. 将环氧化合物用四氢呋喃溶解, 加入NH₄SCN, 室温搅拌反应24 h, 过柱分离后, 得到光学纯的芴基取代的末端环硫化合物, ee值也均大于97%. 通过元素分析、NMR对产物的结构进行了表征, 也利用旋光仪等测定了产物的旋光度, 并且对反应机理进行了探讨.     

Synthesis of Ajoene Analogues by Novel Synthetic Strategies

Ajoene is a compound found in garlic extracts exhibiting a large range of biological activity. Novel ajoene analogues have been prepared in the search of compounds with superior bioactivity. Modifications include the alteration of the sulfoxide, the central alkene and the terminal allyl groups.     

Synthesis of Methyl Dihydrojasmonate. Ester Directed Baeyer-Villiger Oxidation

The distinguished organoleptic properties of the jasmonoids have helped foment development of synthetic routes.¹ In one of our recent approaches to methyl dihydrojasmonate (1) we assimulated and integrated the acid-catalyzed rearrangement process² of cyclopentadiene-acrylic acid adducts into our scheme.     

4-叔丁氧羰酰胺基-呋喃-2-甲酸甲酯的合成

以呋喃甲醛为起始原料,经过5步反应合成了天然产物Proximicin A的     

A Practical Synthesis of 6-Acetylsalicylic Acid Methyl Ester

A new and efficient synthesis of the title compound is reported. The method includes a regioselective ortho-lithiation step in none polar solvents at an ambient temperature and the overall yield for 5 steps is more than 70% from a commercially available 3-hydroxyacetophenone.     

A Convenient Method for Synthesis Methyl Ester of Naproxen

α-Arylpropionic acids are a class of nonsteroidal anti-inflammatory drugs with a substantial size of market. Ibuprofen and naproxen are the important members of this family. Since carbonylation catalyzed by transition metal complexes provides an environmentally benign process for their synthesis, there have been numerous patents and publications related to the carbonylation of alcohols and olefins to produce α-arylpropionic acids or their esters^[1-4]. We have studied the carbonylation of α-(6'-methoxy-2'-naphthyl) ethanol to methyl ester of naproxen using PVP-PdCl₂-CuCl₂/PPh₃ catalyst system. Good conversion and selectivity were obtained under mild conditions.     

光学纯反式-(+)-水合蒎醇的新方法合成

以3,5-二羟基-4-甲基苯甲酸甲酯为原料,通过7步反应,高产率地合成了反式-(+)-水合蒎醇[(+)-1],其结构通过IR,MS和NMR等技术进行了确认,该化合物的光学纯度e.e.高达99%.     

Synthesis and Antitumor Activity of Tanshinone Analogues

8, 8-Dimethyl-5, 6, 7,8-tetrahydrophenanthrene-3, 4-dione (3) and 8, 8-dimethyl-2- ( 1-hydroxy ethyl) -5,6, 7, 8-tetrahydrophenanthrene-3,4-dione (4), two analogues of the antitumor active tanshinone, were synthesized from anisole. The synthesized compounds 3 and 4 were shown to be highly active against leukemia P-388 cell fine as assayed by in vitro MTT method.     

单螺环哌嗪季铵盐类化合物的合成及镇痛活性研究

为寻找镇痛活性更好的化合物,以前期发现的螺环哌嗪季铵盐类化合物1为先导物,设计合成了8个未见文献报道的衍生物.通过1H NMR,13C NMR和元素分析或高分辨质谱确定了化合物的结构.利用小鼠醋酸扭体模型初步评价了它们的镇痛活性,构效关系研究表明,苯环上的羟基是关键的药效团,与开链季铵盐相比,螺环季铵盐结构对活性更有利;扩大螺环和引入取代基对活性不利.