Synthetic Communication: Synthesis of Optically Pure Analogues of D-Arginine Methyl Ester with Antiarrhythmic Activity

The synthesis of the methyl esters of optically pure trans and cis 4-guanidinocyclohexylglycine as rigid analogues of D-arginine methyl ester are described.     

N-(Benzyloxycarbonyl)-L-vinylglycike Methyl Ester from L-Methionine Methyl Ester Hydrochloride

A reproducible, large scale and practical synthesis of N-(benzyloxycarbonyl)-L-vinylglycine methyl ester starting from L-methionine methyl ester hydrochloride is described.     

Synthesis, Photoreactivity and Cytotoxic Activity of Caged Compounds of L-Leucyl-L-Leucine Methyl Ester, an Apoptosis Inducer

I,-Leucyl-L-leucine methyl ester (Leu-Leu-OMe), an apoptosis inducer in natural killer cells and macro-phages, was caged with trans -o-hydroxycinnamoyl (3ad), trans-o -mercaptocinnamoyl (4) and o -nitrobenzyl derivatives (5a, b), and the photochemical reactivity of these derivatives in phosphate-buffered saline containing 1% dimethyl sulfoxide and their immunological properties were studied. All of the derivatives exhibited absorplion at wavelengths longer than the UVB region. Although 3a–d and 4 were expected to isomerize to a cis isomer, which thgn cyclizes intramolecularly to give Leu-Leu-OMe and a coumarin derivative, cyclization efficiency was not satisfactory except for 3a. However, 3a itself caused necrosis (cell swelling) of U937 cells (a myeloid cell line). In contrast, 5a and b released Leu-Leu-OMe quickly and efficiently and did not affect U937 cells. Although irradiated 5b induced necrosis, irradiated 3a and 5a induced apoptosis in these cells, as evidenced by a decrease in cell size.     

4-(N-乙基-3-甲基苯胺基）丁酸甲酯的合成

以γ-丁内酯为起始原料,经开环氯化和醇解反应合成4-氯丁酸甲酯（2）; 2与N-乙基间甲苯胺经亲核取代反应合成了4-(N-乙基-3-甲基苯胺基）丁酸甲酯,纯度97.5%,总收率75.3%,其结构经¹H NMR确证。     

Synthesis of a Novel Acetylenic Ester,Methyl (E)-5-Octadecen-7,9-Diynoate

We, herein, report synthesis of methyl ester of (E)-5-octadecen-7,9-diynoic acid, one of the novel acetylenic fatty acids of Paramacralabium caeruleum root bark with unique biological activity, by coupling synthesized C₁ to C₈ fragment with 1-decyne.     

"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。     

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...     

胆酸甲酯(甲基)丙烯酰基衍生物的合成

以(甲基)丙烯酰氯为酰化剂,三乙胺做缚酸剂合成了分子中含有1~3个(甲基)丙烯酰基的胆酸衍生物。结果显示,以酰氯作酰化试剂,胆酸甲酯分子中3个羟基的反应活性顺序是:C3-OH>C12-OH>C7-OH。     

氘代甲基萤火虫荧光素的全合成

以2-氰基-6-甲氧基苯并噻唑为原料,经脱甲基、氘甲基化,与D-半胱氨酸盐酸盐水合物反应合成了新化合物——氘代甲基萤火虫荧光素,总收率46%,对映选择性100%,其结构经1H NMR,FT-IR和MS表征。     

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).     

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 Chlorophyll a Labeled at C(32) from Pheophorbide a Methyl Ester

[3²-¹⁴C]Chlorophyll a ( 10b ) was synthesized from pheophorbide a methyl ester ( 5a ) in a seven-step partial synthesis. The key intermediate pheophorbide d methyl ester ( 6 ) was obtained by ozonolysis of the vinyl group of 5a in 91% yield. Selective reduction of the CHO group of 6 gave the corresponding alcohol 7 , and conversion of the latter to the phosphonium bromide 8 yielded after Wittig reaction with [¹⁴C]paraformaldehyde, [3²-¹⁴C]pheophorbide a methyl ester ( 5b ). The final transformation to the title compound was achieved by acid hydrolysis of 5b , esterification with natural phytol to [3²-¹⁴C]pheophytin a ( 9b ), and eventual insertion of a Mg²⁺ ion.     

Tandem Intramolecular Benzyne-Furan Cycloadditions. Total Synthesis of Vineomycinone B(2) Methyl Ester

We have exploited tandem intramolecular benzyne-furan cycloadditions employing three different benzyne precursors to generate substituted bisoxabenzonorbornadienes in a single operation. The regiochemical outcomes in these Diels-Alder reactions were effectively controlled by using disposable silicon tethers to link the reacting benzyne and furan moieties. Two different methods for converting the intermediate bisoxabenzonorbornadienes to substituted anthrarufins were developed. The first tactic entails the initial cleavage of the silicon tethers followed by regioselective ring opening of the oxabicycloheptadienes and oxidation of the central ring giving the target anthrarufin, whereas the second features the regioselective ring opening of the oxabicycloheptadienes followed by protiodesilylation and oxidation. When the starting furans bear carbohydrate substitutents, this new methodology enables the rapid assembly of the glycosyl-substituted aromatic cores of complex C-aryl glycoside antibiotics from simple starting materials. The utility of this novel approach to anthrarufins and C-aryl glycosides is exemplified in a triply convergent synthesis of vineomycinone B₂ methyl ester.     

Synthesis of （2R,4R）—2—N—tert—Butyloxycarbonyl Amino—4,5—epoxido—valeric Acid Methyl Ester

The stereoselective synthesis of (2R,4R)-2-N-tert-butyloxycarbonyl amino-4,5-epoxido-valeric acid methyl ester 8,which is the key intermediate for the synthesis of (2′S,2R)-3-trans-nitrocyclopropyl-alanine,was first accomplished.     

[反]-β-法尼烯类似物的设计、合成与生物活性研究

对[反]-β-法尼烯(EBF)类似物的骨架结构原子进行改造,引入吡虫啉系列活性基团,设计合成了13个结构新颖的EBF类似物,并对其生物活性进行了研究.结果表明,这些化合物对蚜虫具有明显的抑制活性,尤其在低浓度时活性更明显,如质量浓度为25mg/L时,I₁₀和I₁₃对蚜虫的抑制率分别为93.1%和87.1%,远高于同浓度下吡虫啉的抑制率(66.7%).     

弥拜霉素类似物的合成、表征和杀虫活性研究

以弥拜霉素类似物依维菌素为原料,根据类同合成法和亚结构连接法原理,对依维菌素进行脱糖,再与相应的酰氯进行酯化、肟化反应制得两个系列弥拜霉素类似物化合物4Ia～5IId,所有目标化合物都通过核磁共振氢谱、高分辨质谱的确认,并分别对朱砂叶螨(Tetranychus cinnabarinus)、南方粘虫(Mythimna sepatara)和蚕豆蚜(Aphis fabae)进行室内杀虫活性测定,结果表明所有衍生物均表现出不同程度的杀虫活性,其中化合物4IIa和4IIb对粘虫和蚜虫表现出很高的杀虫活性.     

含5-氟尿嘧啶短肽的合成及其抗肿瘤活性研究

肿瘤细胞与正常细胞在酶系上存在差别,利用这些差别,chakravarty等设计并合成缬-亮-赖三肽与苯二胺氮芥等抗肿瘤原药结合的抗肿瘤短肽药物,它们的抗肿瘤选择性比苯二胺氮芥等抗肿瘤原药提高5～7倍。我们在前文中报道了5-氟尿嘧啶乙酰(丙酰)二肽和三肽的合成及抗动物肿瘤试验,初步结果表