一种新的保护的2-脱氧-2-氨基葡二糖合成

以氨基葡萄糖盐酸盐为原料制得糖基给体3,4,6-三-氧-乙酰-2-脱氧-2-(2,2,2-三氯乙氧)甲酰胺基-α-D-吡喃葡萄糖基三氯乙酰亚胺酯(5)和糖基受体烯丙基-4,6-氧-亚苄基-2-脱氧-2-(2,2,2-三氯乙氧)甲酰胺基-α-D-吡喃葡萄糖苷(7).在三甲基硅基三氟甲基磺酸酯(TMSOTf)条件下,给体5与受体7反应得到一种新的二糖烯丙基-3,4,6-三-氧-乙酰-2-脱氧-2-(2,2,2-三氯乙氧)甲酰胺基-β-D-吡喃葡萄糖-(1→3)-4,6-氧-亚苄基-2-脱氧-2-(2,2,2-三氯乙氧)甲酰胺基-α-D-吡喃葡萄糖糖苷(10),收率为39.2%.当7在无水BaO和Ba(OH)2·8H2O的条件下与BnBr进行3-OH苄基化反应时,却得到了烯丙基-3-氧-苄基-4,6-氧-亚苄基-2-脱氧-2-羟甲酰胺基-α-D-吡喃葡萄糖苷(8).改用Ag2O条件下与BnBr进行苄基化,得到预期的烯丙基-3-氧-苄基-4,6-氧-亚苄基-2-脱氧-2-(2,2,2-三氯乙氧)甲酰胺基-α-D-吡喃葡萄糖苷(9),从而避免了氨基保护基三氯乙氧甲酰基的水解.标题化合物10对枯草芽孢杆菌、葡伎根霉等微生物有一定的抑制作用.     

New Polyol Syntheses

1,3,5,…︁-Polyol structures are characteristic components of polyene macrolide antibiotics such as filipin III ( 1 ). Iterative stereoselective alkylation of lithiated cyanohydrin acetonides and subsequent reductive decyanation is one possibility for the stepwise synthesis of this class of natural products characterized by a polyol framework of 1,3-diol units.     

几种新的四苯(基)苯基有机硅化合物的研究

本工作以双乙烯基四甲基二硅氧烷、乙烯基甲基二氯硅烷、乙烯基七甲基环四硅氧烷分别与四苯基环戊二烯酮通过Diels-Alder反应合成了相应的四种四苯(基)苯基有机硅化合物(Ⅰ-Ⅳ)。并由化合物Ⅲ又制成了三种化合物Ⅴ一Ⅶ。对这些新化合物的组成、结构作了相应的分析、测试和鉴定。还对有些Diels-Alder反应做了改进,从封管反应改为常压反应后,效果更佳。     

New Syntheses of Diazo Compounds

Diazo compounds (R¹R²C?N₂) are known as versatile and useful substrates for an array of chemical transformations and, therefore, diazo chemistry is still far from losing anything of its long‐standing fascination. In addition to many studies on the subsequent chemistry of the diazo group, the inventory of methods for the preparation of diazo compounds is continuously supplemented by new methods and novel variations of established procedures. Several of these synthetic approaches take into account the lability and remarkable chemical reactivity of certain classes of diazo compounds, and environmentally more benign procedures also continue to be developed.     

New Oxetane and Tetrahydropyran Syntheses

The base catalysed rearrangement of the benzyl ethers of oxiranylcarbinols and their homologues provides convenient routes to oxetan-3-ylcarbinols and tetrahydropyran-4-ols.     

Syntheses of 2-hydroperoxy-and 2-hydroxy-2H-imidazoles

Oxidation of fully substituted imidazoles 1 by singlet oxygen gives in good yield fully substituted 2-hydroperoxy-2H-imidazoles 2 . Reduction of 2 by triphenylphosphine leads to 2-hydroxy-2H-irnidazoles 3 . Limitations of the methods are reported.     

New Indigo Syntheses. Preliminary Communication

Three novel routes for the preparation of the dyestuff indigo are described. Two of the methods use isatoic anhydride, the third one styrene as starting materials. Key reactions are acylation of both dimsyl and nitromethane anions, Pummerer rearrangement and Nef reaction. A novel nitration of styrene is the basis of the third method.     

蛋白酶在有机合成中应用的新进展

介绍了有机溶剂中酶促反应的一些基本概念, 总结了酶促反应的发展情况, 归纳了近几年来将蛋白酶应用于有机合成的一些新策略。     

Syntheses of E-2-Nitroethenyltrimethylsilane

Three routes were explored for the conversion of tri-methylvinylsilane (1) to E-2-nitroethenyltrimethylsilane (2). In each case, 2 was afforded by base-induced vicinal elimination within the adducts arising from 1 plus (a) NO₂C1 (b) N₂O₄ or (c) HgC1₂ + NaNO₂.     

嘌呤2位卤素取代衍生物的合成

嘌呤2位卤素取代衍生物的合成;嘌呤;重氮化;合成;杀菌活性     

Microwave-Assisted Syntheses of 2-Phenylbenzothiazoles

A new and easy synthetic route to 2-phenylbenzothiazoles has been achieved by direct thiation of benzoyl derivatives of aniline, various substituted anilines, and 1-naphthylamine under microwave irradiation. The oxidative cyclization using elemental sulfur in the presence of a catalytic amount of iodine is inexpensive and worked well for a number of anilides.     

Syntheses of methyl-2-furylketones

, -Dibromomethyl-2-furylketone and its 5-nitro derivatives are prepared by brominating the appropriate ketones in CCl₄.,-diiodomethyl-2-furylketone and its 5-nitro derivative are synthesized by the action of iodine on the appropriate diazoketones, and in the case of the 5-nitro derivative along with the diiodoketone is isolated the corresponding glyoxal. 5-Nitro-2-furylglyoxal is also obtained by the action of dimethylsulfoxide on bromomethyl-5-nitro-2-furylketone.For Part XII see [1]     

Syntheses of 2-Bromopyrene and 2-Hydroxypyrene

Regiospecific monobromination of 4,5,9,10-tetrahydropyrene in the 2-posiuon is accomplished in aqueous dimethylformamide. Conversion of the previously unknown 2-bromo-4,5,9,10-tetrahydropyrene to the title compounds is described.     

Syntheses of New Multisubstituted 1-Acyloxyindole Compounds

The syntheses of novel 1-acyloxyindole compounds 1 and the investigations on reaction pathways are presented. Nitro ketoester substrate 2, obtained in a two-step synthetic process, underwent reduction, intramolecular addition, nucleophilic 1,5-addition, and acylation to afford 1-acyloxyindoles 1 in one pot. Based on the systematic studies, we established the optimized reaction conditions for 1 focusing on the final acylation step of the intermediate 1-hydroxyindole 8. With the optimized conditions, we succeeded in synthesizing 21 examples of new 1-acyloxyindole derivatives 1 in modest yields (Y = 24 − 35%). Among the 1-acyloxyindole compounds, 1-acetoxyindole compounds 1x were generally unstable, and their yields were relatively lower than the other 1-acyloxyindoles. We expect that a bulkier alkyl or aromatic group on R² could stabilize the 1-acyloxyindole compounds. Significantly, one-pot reactions of a four-step sequence successfully generated compounds 1 that are all new and might be difficult to be synthesized otherwise.     

A Convenient Syntheses of some New Substituted Guanidines

The cyanamides of 2,6-dimethylaniline, N-methyl-α, β -naphthylamines, 2-methylpiperidine and indoline yielded their respective guanido derivatives on treatment with dry ammonia and their structures have been characterized through spectral studies.     

A New Route to Syntheses of Zeolite Beta

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取代甲基亚磺酰基苯并咪唑类化合物的合成

合成了一系列取代甲基硫代苯并咪唑类化合物，并在过氧乙酸的氧化下得到了 取代甲基亚磺酰基苯并咪唑类化合物，收率较好(79%～97%)，代替了用间氯过氧苯 甲酸进行氧化，反应过程稳定，降低了成本。