一种新的合成12-氧代-1,15-十五内酰胺的方法

设计了一种新的合成12-氧代-1,15-十五内酰胺(4)的方法, 即以α-硝基环十二酮(1)为原料, 经与丙烯腈的Michael加成, 氰基选择性还原为氨基后扩环, 再经Nef反应合成了4, 总收率为28%.     

A Facile Synthetic Route to L-Phosphinothricin

Phosphinothricin, the active ingredient of the well known broad-spectrum herbicideglufosinate-ammonium, is a naturally occurring amino acid possessing the uniquemethylphosphinate moiety, and its strong herbicidal activity has been attributed to anability to inhibit glutamine synthetase in plants and bacteria1. Further research showedthat L-enantiomer of phosphinothricin was the carrier of the activity, whereas the D formonly had a small action2, therefore the stereoselective synthesis of L-pho…     

A New Synthetic Route to 5-Isoxazolamines

5-Isoxaz0lamineshavebeenusedasintermediatesforthesynthesis0fderivatives0fantihistaminic,analgetic,antibacterial,insecticidal,herbicidalandfungicidalactivity'.Usuallytheyaresynthesizedbytheintramolecularcondensation0fhydr0xylamineand0-nitrilegr0up'.Otherapproaches,suchasreductivecyclizati0nofZ-a-cyano-6-nitroethylenesandIithiumaIuminumhydridereduction0f3-cyanooxazoleshaveals0beenrepoFted'-'.HerewerepoFtanewsyntheticrouteofthesecompounds.Ohn0andNaruse7havereportedthatthereactionof2-chlorocycl…     

A New Synthetic Route to Selected Indenones

Indenones are useful intermediates in the synthesis of several natural products, e.g. gibberellins (1) and steroid hormones with a C-nor-D-home system (2). Despite the nernerous methods for indenone synthesized, or the yields was much lower as mentioned in earlier reports (1)(4). One of the difficulties of the usual methods is the required electrophilic cyclization meta to a methoxyl substiruent. House (5) deals with these difficulties in more detail. In our method the synthesis of 6-methoxyinde-nones is effected by substitution dara to methoxyl function.     

A New Synthetic Route to (±)-Perhydrohistrionicotoxin

Starting from ethyl 2-cyclohexen-1-carboxylate ( 3 ) the total synthesis of the perhydrohistrionicotoxin intermediate 23 was achieved in 25% overall-yield. The two key steps involve a positionally specific addition of HOBr to the oxime-olefin 7 and the alkylation of bromooxime 17 with 1-lithio-1-butyne. The latter represents a novel method for stereospecific and position-specific introduction of a nucleophilic butyl equivalent in α-position to a ketonic carbonyl group.     

4-溴代苯酐的合成新方法

将4-硝基邻苯二甲酰亚甲胺（4-NPI）用铁粉还原为4-氨基邻苯二甲酰亚甲胺 ，再在氢氧化钠水溶液中水解成4-氨基邻苯二甲酸钠。4-氨基邻苯二甲酸钠在氢溴 酸中经Sandmeyer反应合成4-溴代苯酐。产品纯度高，是合成4-溴代苯酐的一个比较 理想的方法。     

A New Pathway to Synthesize Cyclomercurated Ferrocenylimines Containing Heterocyclic Ring

The cyclomercurated ferrocenylimines containing heterocyclic ring were prepared by the condensation of cyclomercuration of acylferrocene with the appropriate heterocyclic amine.This procedure provides an efficient method for the synthesis of cyclomerucurated ferrocenylimines containing heterocyclic ring which are difficultly synthesized by the conventional method.The reaction mechanism is proposed.     

邻氯苯甲腈的新合成法

以邻氯溴苯为起始原料,选用K4[Fe(CN)6]为氰基化试剂,Pd/C催化反应制得邻氯苯甲腈。 考察了温度、碱、催化剂的用量和原料比等对反应的影响,确定了较佳反应条件。 邻氯溴苯转化率达98.5%,产物邻氯苯甲腈得率95.1%。     

A Route to Amino Functionalized Hypericin Derivatives and their Chemical and Photochemical Properties Pertaining to Photodynamic Therapy

Summary. Syntheses of amino functionalized hypericin derivatives could be achieved starting from the recently prepared emodin derived 1,3,8-trimethoxy-6-amino-9,10-anthraquinone. Our strategies for the preparation of 10,11-didemethyl-10,11-diaminohypericin, 10,11-didemethyl-10,11-di(acetylamino) hypericin, and its hypericinoidic diazepine derivative include synthetical modifications on the levels of the anthraquinone, anthron, and the phenanthroperylenequinone system itself. The chemical as well as photochemical properties of these unique hypericin derivatives, which might constitute new photodynamic therapy agents, are reported.     

New Synthetic Route to Polyhedral Organylsilsesquioxanes

Hydrosilation of methylenecyclohexane and hex-1-ene by octa(hydridosilsesquioxane) catalysed by hexachloroplatinic acid is a new route to polyhedral organylsilsesquioxanes. Quantitative yield of octa(cyclohexylmethylsilsesquioxane) is reached. This reaction opens a vast field of yet unknown polyhedral silsesquioxanes.     

A New Synthetic Method for N—Substituted Selenoamides

Benzotriazole,aldehydes and primary selenoamides react together with elimination of water to form 1:1:1 adducts which are reduced smoothly by NaBH4 to give the N-substituted selenoamides in good yield.     

A Facile Synthetic Approach to Two Chalcones

Some Vitex species have long been used in folk remedies due to their excellent antibiotic activities1. Chalcones also have good activities such as immunological action2. 2? 4?dihydroxy-4, 6?dimethoxy chalcone 1 and 4?hydroxy-4, 2? 6?trimethoxy chalcone 2 were natural products which were firstly separated from the aerial parts of Vitex leptobotrys in North Vietnam by Trinh3. To our knowledge, no synthetic method about these compounds was reported. Herein we report a convenient synthetic r…     

异黄酮类化合物的合成新方法

提出了一种新颖的合成异黄酮类化合物1, 2和3的方法. 以1,3-二甲氧基苯或1,3,5-三甲氧基苯为原料, 经Hoesch反应或Friedel-Crafts酰化反应、脱甲基反应、增碳关环一系列反应得到关键的甲氧基异黄酮化合物, 然后甲氧基异黄酮经过不同浓度氢溴酸的选择性水解反应制得含一个或多个羟基的异黄酮类化合物.     

磷酸特地唑胺的合成新方法

以(5R)-3-(4-溴-3-氟苯基)-5-羟甲基噁唑烷-2-酮为起始原料,在[PdCl₂(dppf)]·CH₂Cl₂催化下与联硼酸频那醇酯反应得到硼化物,继而与5-溴-2-(2-甲基-2H-四唑-5-基)吡啶进行Suzuki反应得到特地唑胺,收率82.9%。 分别考察了催化体系对硼化反应和Suzuki反应的影响,确定了较佳的反应条件。 特地唑胺与二苄基N,N-二异丙基亚磷酰胺反应得到二苄基保护的磷酸特地唑胺,随后经Pd/C脱苄得到磷酸特地唑胺,总收率66.2%。     

5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的新法合成

以2,6-二氯吡啶为起始原料,经肼基化、还原、硝化、Nietzki-Dietschy环合4步反应得到5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物.结合反应机理讨论了还原、硝化、Nietzki-Dietschy环合反应的影响因素,获得了合成-.氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的最佳工艺条件,目标产物的总收率为59.2%.用1H NMR、MS和IR谱对5-氨基-6-硝基-[1,2,5]噁二唑并[3,4-b]吡啶-1-氧化物的结构进行了表征.     

A Facile Synthesis Route to 1,3-dichlorodisilazanes

Since the pioneering work of Verbeek', considerable attention has focussed on researchdevoted to the preparation of silicon nitride- and silicon carbide- based ceramic materials.Owing to their promising potential for the formation of high-purity non-oxide siliconbased ceramics, organosilicon compounds (precursors) have attracted considerableinterest in recent years 2. The structures and the chemical composition of the precursorsstrongly effect the properties of the final ceramic materials. Acc…     

一种合成3,5-二氨基吡啶及3,5-二甲氧羰基氨基吡啶的新路线

以3,5-二甲基吡啶为起始原料,经氧化、酰胺化,酰胺在不同的霍夫曼降解条件下合成3,5-二氨基吡啶及3,5-二甲氧羰基氨基吡啶,总收率分别为64%和68%。利用1H NMR、MS/MS、IR等方法对各化合物的结构进行了表征。讨论了氧化反应及霍夫曼降解反应的主要影响因素。反应均在常压下进行,反应条件温和,后处理简单,效率高。     

The First Total Synthesis of 3-Oxo-11, 12, 13-trihydroxyeudesm-4-ene

The first total synthesis of 3-oxo-11, 12, 13-trihydroxyeudesm-4-ene, a highly oxygenated natural eudesmane, was described.