A New Method for the Synthesis of gem-Dihydroperoxides

The tungstic acid-catalyzed reaction of ketals with hydrogen peroxide provides a convenient and efficient method for preparing gem-dihydroperoxides.     

一种非西他滨的合成方法

非西他滨(Fiacitabine,FIAC)是一种嘧啶核苷类似物,具有抗各种疱疹病毒的活性。本文以2-脱氧-2-氟-三苯甲酰基-α-D-阿拉伯呋喃糖为原料,常温条件下,经过溴化氢醋酸溶液溴化得到2-脱氧-2-氟-三苯甲酰基-α-D-溴化阿拉伯呋喃糖(4);再以胞嘧啶为原料经过碘化、Bz-保护得到N-(5-碘-2-氧代-1,2-二氢嘧啶-4-基)苯甲酰胺(5),最后中间体4和5反应后脱保护基得到非西他滨。整条路线反应原料廉价,反应步骤少,选择性高,总收率高达43%。     

一种合成脱水糖醇的新方法

以四苄基糖(或2,3:5,6-二异丙叉基-D-甘露糖)为起始原料,经过NaBH4或LiAlH4还原、单对甲苯磺酰化、分子内环醚化反应、脱保护等步骤合成了四个脱水糖醇,总产率55%～75%,其结构经1H NMR,13C NMR,HSQC和NOESY表征.     

邻-二氨基烯的合成新方法

以芳香醛,硫和胺为起始原料,经Willgerodt—Kindler反应合成硫代酰胺,硫代酰胺在钐／二碘化钐试剂促进下发生脱硫偶联反应,得到邻-二氨基烯类化合物。其结构经1^H NMR,IR,MS和元素分析表征。     

A New Method for the Synthesis of Ketone Diperoxide

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苯磺酸贝他斯汀的合成新方法

探索了一条合成苯磺酸贝他斯汀的新路线。以2-吡啶甲酸、氯苯为原料,经过9步反应合成苯磺酸贝他斯汀,其中关键消旋中间体(4-氯苯基)(2-吡啶基)甲氧基哌啶,经过D-DBTA拆分,可得到光活性(S)-(4-氯苯基)(2-吡啶基)甲氧基哌啶(>99% ee)。同时,(R)-(4-氯苯基)(2-吡啶基)甲氧基哌啶经过消旋化后再次拆分得到(S)-构型产物。该合成方法反应条件温和,具有工业化生产前景。最终产物结构由¹H NMR, ¹³C NMR和HR-MS(ESI)确证。     

N-氰基-亚胺酯衍生物的合成新方法

以甲醇为溶剂,N-溴代丁二酰亚胺为氧化剂,单氰氨和β-硝基芳基乙烯为原料,合成了一系列N-氰基.亚胺酯衍生物,其结构经<'1>HNMR,<'13>CNMR和HR-MS确证.     

A New Method for the Synthesis of Furan Derivatives

Substituted 2-chloro-4-formyl-5-arylfuran and 2,5-dimethyl-3-formylfuran derivatives were synthesised from their corresponding substituted 3-benzoylpropionic acid and acetonylacetone using Vilsmeier reagent in good yields.     

合成2-氟腺嘌呤的新方法

从2-氨基-6-氯嘌呤出发,通过叠氮化反应合成2-氨基-6-叠氮嘌呤(3),3在希曼反应中完成氟对氨基的取代得到2-氟-6-叠氮嘌呤(4),4的叠氮基被还原为氨基制备出目标化合物2-氟腺嘌呤,总收率39.3%。     

合成3,3''''-二吲哚基苯基甲烷的新方法

以无水乙醚为溶剂,室温下无水三氯化铝催化N-(2-氯乙基)苯甲醛亚胺与吲哚反应,合成了3,3'-二吲哚基苯基甲烷和6,12-二苯基吲哚[2,3-b]咔唑,其结构经1H NMR,IR和MS表征.     

不饱和的钛杂五元环化含物合成的新方法

关于钛杂环化合物的合成与反应,在文献中曾有一些报道。这类化合物,无论在有机合成上或对于阐明某些有机化学反应和催化聚合机理,都具有重要的作用。这类钛杂环化合物的合成,通常是用二氯二茂钛与双碱金属     

合成N,N'-二环己基碳二亚胺的新方法

环己胺与三光气反应合成了环已基异氰酸酯(2):在有机磷催化剂存在下,2经缩合反应制得N,N'-二环己基碳二亚胺,收率87%,纯度98%.     

A New Method for the Synthesis of Antihypercholesterolemic Agent Simvastatin

A new synthetic method for the preparation of the cholesterol‐lowering drug simvastatin from the naturally occurring lovastatin is reported. The synthesis employs first the protection of the OH group of lovastatin ( 1 ) and then the protection of the lactone C?O group to prevent enolization via conversion to the orthoesters 4a and 4b . Alkylation of the 2‐methylbutyrate side chain is then successfully achieved. Removal of the protecting groups affords antihypercholesterolemic agent simvastatin ( 2 ).     

A New Method for the Synthesis of Symmetrical Disubstituted Pyrazines

Through the self‐condensation of α‐amino aldehydes, the synthesis of symmetrical disubstituted pyrazines was achieved in a three‐step one‐pot reaction. The α‐amino aldehydes were easily obtained by treating methyl esters of natural α‐amino acids with diisobutylaluminium hydride.     

A New Method for the Synthesis of Oxadiazine Insecticide Indoxacarb

9‐Fluorenylmethoxycarbonyl was a good protecting group in the field of chemical industry. In the present paper, a new approach for the synthesis of oxadiazine insecticides indoxacarb used 9‐fluorenylmethoxycarbonyl as protected group, and triphosgene for chloroformylation. A convenient synthesis of 9‐fluorenylmethoxycarbonylhydrazine can be achieved by the nucleophilic substitution reaction of 9‐fluorenylmethyl chloroformate and hydrazine hydrate. 4a‐Methyl‐2‐(9‐fluorenylmethyl)‐7‐chloro‐indeno [1,2e][1,3,4]oxadia zine‐2,4a (3H,5H)‐dicarboxylate can be produced via ketone ‐hydrazine crosslink reaction and cyclization. A preparation of carbamic acid‐(chlorocarbonyl)‐[(4‐trifluoromethoxy) phenyl] me ester can be obtained by the chloroformylation of triphosgene. Finally, the deprotection of 9‐fluorenylmethoxy carbonyl and condensation with carbamic acid‐(chlorocarbonyl)‐[(4‐trifluoromethoxy) phenyl] me ester can afford indoxacarb in good yield. A new method for the synthesis of oxadiazine insecticides indoxacarb used 9‐fluorenylmethoxycarbonyl‐protected group to produce 9‐?fluorenylmethoxycarb?onylhydrazine, then through the ketone–hydrazine crosslink reaction, cyclization, deprotection, chloroformylation, and condensation in good yield.     

A New Method for the Synthesis of Substituted 3,5-Diphenylisoxazoles

3,5-diphenylisoxazole has been synthesised from hydroxylamine compound (1) via a novel addition compound (2). Probable mechanism is discussed.     

合成紫杉烷的新方法

由偶氮二异丁腈引发次磷酸产生次磷酸根自由基,以链式自由基反应机制脱除紫杉烷类化合物结构中的含氧基团,简单、高效地合成了紫杉烷.