Highly Stereoselective Synthesis of trans-3-Aryl-4-carbethoxy-2,3-dihydro-2-fur-2＇-oyl-5-methylfurans

Multi-substituted dihydrofurans are valuable intermediates for the synthesis of natural products and pharmaceuticals. Considerable attention has been focused on the development of efficient and regioselective methods for their preparation. Using K2CO3 as a base, with the reaction of fur-2-oylmethyltriphenylarsonium bromide 1 and ethyl 2-acetyl-3-arylacrylate 2 in tetrahydrofuran at room temperature, we found an efficient protocol was achieved to synthesize trans-3-aryl-4-carbethoxy-2,3-dihydro-2-fur-2＇-oyl-5-methylfurans 3 in good yield with high stereoselectivity. The structure of compound 3 was confirmed by IR, ^1H NMR, MS and HRMS. The mechanism for the formation of 3 was proposed.     

Fe（Ⅲ）－TEA－5－Br－PADAP－H_2O_2体系中催化波的研究及其应

在０．２ｍｏｌ·Ｌ￣（－１）ＮＨ＿４Ｃｌ－ＮＨ＿３·Ｈ＿２Ｏ底液中，（ｐＨ为９．２６），得到一个极为灵敏的Ｆｅ（Ⅲ）－ＴＥＡ－５－Ｂｒ－ＰＡＤＡＰ－Ｈ＿２Ｏ＿２配合吸附催化波，其峰电位为－０．７１Ｖ（ｖｓ．ＳＣＥ）。铁浓度在１．８×１０￣（－１０）～５．４×１０￣（－６）ｍｏｌ·Ｌ￣（－１）范围内与二阶导数波高呈线性关系。对该极谱波的性质进行了研究，证明是一种配合吸附催化波，并成功地应用于各类水样，钒催化剂中微量或痕量铁的测定。     

Hydroxylation of nigranoic acid to 6β-hydroxynigranoic acid by Caryospora carllicarpa YMF1.01026

Microbial transformation of nigranoic acid by Caryospora carllicarpa YMF1.01026 afforded the new derivative 6β-hydro-xynigranoic acid. Its structure was elucidated by spectroscopic methods.     

表面膨胀粘度的测定研究

用不同浓度的NaCl和表面活性剂直链的十二烷基苯磺酸钠(LAS)、稳定剂聚丙烯酰胺和水所组成的泡沫体系为研究对象,通过表面压松弛的方法,利用计算机数据拟合,得到了计算表面膨胀粘度的方法。     

复合Fe2O3纳米粒子的高分子微球的结构表征

近年来，复合有机、无机粒子的高分子微球及其特殊性质越来越引起人们的兴趣与关注［1］．获得有机、无机复合微球的方法很多，如在无机粒子存在下的乳液或无皂乳液聚会[2，3]，通过可聚合的表面活性剂在粒子表面形成胶囊化层[4]以及共沉淀法等[5]．这些无机粒子包括氧化钛、氧化铁、氧化铝及氧化硅等．Haga等[6]增发现包覆在聚合物粒子中的CdS与其本体的光电性质不同；单分散的聚合物微球可以在基片上被组装成二维乃至三维有序的结构[7]．这为信息存储、立体印刷等领域提供了新途径．因此，将无机粒子与聚合物复合成为功能化粒子是一项有…     

用共振电离飞行时间质谱仪分析土壤中超痕量气态金

采用激光共振电离飞行时间质谱技术（简称ＲＩＳ－ＴＯＦ技术）对土壤中超痕量气态金的含量进行了分析研究。ＲＩＳ－ＴＯＦ谱仪具有极高的灵敏度和很强的选择性，避免了对样品的预富集过程。本文给出了该谱仪对金元素的检测限和６５个土壤中气态金样品的分析结果，以及用中子活化法随机抽样检查的结果。     

Alkylation of Benzene with Propene over Hβ Zeolite──The Effect of Reaction Conditions on the Distribution of Products

ＡｌｋｙｌａｔｉｏｎｏｆＢｅｎｚｅｎｅｗｉｔｈＰｒｏｐｅｎｅｏｖｅｒＨβＺｅｏｌｉｔｅ──ＴｈｅＥｆｆｅｃｔｏｆＲｅａｃｔｉｏｎＣｏｎｄｉｔｉｏｎｓｏｎｔｈｅＤｉｓｔｒｉｂｕｔｉｏｎｏｆＰｒｏｄｕｃｔｓＭＡＪｕｎ，ＳＨＥＮＪｉａｎ－ｐｉｎｇ，ＳＵＮＴ...     

Alkylation of benzene with 1-hexene in acidic ionic liquid systems: Et3NHCl-FeCl3and Et3NHCl-AlCl3ionic liquids

Summary The alkylation of benzene with 1-hexene has been investigated in different triethylamine hydrochloride-ferric chloride (Et₃NHCl-FeCl₃) and triethylamine hydrochloride-aluminium chloride (Et₃NHCl-AlCl₃) ionic liquids. Both high catalyst activity and monoalkylation selectivity were observed for these two type of ionic liquids. Systems prepared by modification with HCl in Et₃NHCl-FeCl₃ionic liquids prove to be very suitable solvents and catalysts for the reaction. When employing Et₃NHCl-AlCl₃ionic liquids as catalysts, the reaction takes place in biphasic mode with facile catalyst separation and catalyst recycling.     

Two-dimensional protein database of human pancreas

We report here the two-dimensional protein database of human pancreas. The proteins were analyzed by two-dimensional electrophoresis followed by matrix-assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS). Totally, 302 proteins were identified, of which about 27% were enzymes with a broad range of catalytic activities. Several of these are specifically expressed in pancreas, such as pancreatic amylase, pancreatic stone protein, pancreatitis-associated protein, pancreatic lipase, pancreatic elastase, etc. Structural and cytoskeletal proteins are also strongly represented on the gels. Thus, the pancreatic proteome reflects the organ's function. This work paves the way for further studies on pancreatic protein expression in health and disease, such as diabetes and pancreatic cancer.     

微乳液介质—1—（2—吡啶偶氮）—2—萘酚光度法测定汽油中环烷酸铁的含量

本研究了微乳液为介质时，铁与１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）的显色反应。选择７３０ｎｍ处为测定波长，ε为１．４×１０＾４Ｌ．ｍｏｌ＾－＾１．ｃｍ＾－＾１，铁量在０－５０μｇ／２５ｍｌ范围内符合比耳定律，该法适用于汽油中环烷酸铁的测定。