蝉翼藤茎中蔗糖酯成分研究

从云南产蝉翼藤(Securidacainappendiculata)茎的乙醇提取物中分离得到3个蔗糖酯类成分.采用化学方法和现代光谱分析技术(包括UV,IR,ESIMS,FABMS,1D和2DNMR等)鉴定其结构分别为β-D-(3,4-O-disinapoyl)fructofuranosyl-α-D-(6-O-sinapoyl)glucopyranoside(1),β-D-(3-O-feruloyl)fructofura-nosyl-α-D-(6-O-sinapoyl)glucopyranoside(2)和β-D-(3-O-feruloyl)fructofuranosyl-α-D-(6-O-feruloyl)gluco-pyranoside(3).其中,化合物3为新的阿魏酸蔗糖酯,命名为蝉翼藤糖酯A(SecurosideA).     

Addition Reactions of Benzenesulfinic Acid with Glycals and 1,2-Dibromosugars

The addition of benzenesulfinic acid to glycals was investigated under various conditions, and optimized yields of the glycosyl phenylsulfone products were obtained in the presence of tin tetrachloride as a catalyst. Double bond shift (Ferrier rearrangement) occurred in all cases except amicetal, which lacks a substituent at the allylic carbon. Glycosylation of benzenesulfinic acid with 1,2-dibromides was carried out using silver triflate as the promoter, and gave sulfinate esters as products by reaction at oxygen rather than at sulfur. The sulfinate esters were obtained as mixtures of stereoisomers at the stereogenic sulfur atom. Trapping of the sulfinates with carboxylate nucleophiles was observed during attempted oxidation with MCPBA.     

Electrochemically induced processes in the formation of phosphorus acid derivatives. 2. The role of polymerization processes in the electrosynthesis of the esters of phosphorus acids from white phosphorus

The mechanism of the electrosynthesis of phosphate esters from white phosphorus was investigated. It was shown that the reaction takes place by two paths, i.e., monomeric (with the participation of dissolved phosphorus) and polymeric (with the participation of phosphorus on the surface of an emulsion drop). It was established that in an alcohol solution of tetraethylammonium iodide the main part of the final product is formed through an intermediate polymeric compound. It was noticed that by studying the dynamics of the accumulation of the dissolved product during electrolysis it is possible to trace the mechanism of reaction of the phosphorus at the individual stages of the process.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420028 Kazan'. V. I. Ul'yanov-Lenin Kazan' State University, 420028 Kazan'. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1328–1333, June, 1992.     

Acridinium ester chemiluminescence: pH dependent hydrolysis of reagents and flow injection analysis of hydrogen peroxide and glutamate

An automated analysis system is described for the measurement of hydrogen peroxide based on a chemiluminescence reaction with phenyl 10-methylacridinium-9-carboxylate (PMAC). A reversed FIA experimental arrangement is used to establish the operating conditions for the measurement of submicromolar levels of hydrogen peroxide. The carrier stream consists of hydrogen peroxide standards prepared in a pH 9.0, boric acid buffer and the flow rate for this carrier/sample stream is 4 ml/min. Twenty microliters of a 10 mM PMAC solution, prepared in a pH 3 phosphate buffer, are injected into the carrier/sample stream. Hydrogen peroxide mixes with the PMAC reagent in an incubation coil that is constructed by wrapping 107 cm of polyethylene tubing around a 1 cm o.d. plastic rod. The chemiluminescence reaction is then initiated by adding base just before the sample passes in front of a photomultiplier tube (PMT) detector. The calculated limit of detection (S/N = 3) for hydrogen peroxide is 0.25 M. In addition, the pH dependent hydrolysis of the PMAC reagent is characterized by an HPLC method which has been specifically developed for the separation and detection of the hydrolysis products of PMAC. Results indicate that a pH of 3.0 is required for long term stability of the PMAC reagent. Finally, this system has been successfully extended to the measurement of glutamate by coupling a bioreactor column of glutamate oxidase with the hydrogen peroxide detection scheme. A detection limit (S/N = 3) of 0.5 M has been established for glutamate with a throughput of 200 samples per hour.     

Synthesis of Cholesteryl Esters of Heterocyclic Analogs of Cinnamic Acid and Hetaroyloxycinnamic Acids by the Wittig Reaction

The reaction of cholesteryl triphenylphosphonioacetate chloride with heterocyclic aldehydes and hetaroyloxyarenecarbaldehydes in the presence of base gave the corresponding cholesteryl esters of substituted propenoic acids possessing liquid crystal properties.     

A GC/MS Method of Determining Airborne DI-n-Butyl- and DL(2-Ethyl Hexyl) Phthalates

An analytical technique is presented that determines the amount of airborne phthalates in a glass fiber filter. The methodology makes use of a GC/MS system that has been integrated with a dedicated mini-computer.     

Reactivity of Various α-Halo Ketones in One-Pot Synthesis of γ-Iminolactones

The highly reactive 1:1 intermediate generated in the reaction of tert-butyl isocyanide and dialkyl acetylenedicarboxylate is trapped by α-halo ketones to produce halogenated iminolactones as the sole product in good yields.     

The Reaction of 1-Nitro-4-(4-nitrophenylsulfonylmethyl)benzene with α,β-Unsaturated Esters

Under solid-liquid PTC conditions, treatment of 1-nitro-4-(4-nitrophenylsulfonyl-methyl)benzene(1) with α,β -unsaturated esters (2a-h) at 35–75°C gave tandem addition-rearrangement products(3a-h). While at higher temperature(75°C), addition-rearrangement-addition products (4a-b) were obtained when acrylates were used. Finally a possible mechanism is proposed.     

Organic Reactions in Ionic Liquids： An Efficient Method for the Synthesis of Phenacyl Esters by Reaction of Carboxylic Acids with α-Bromoacetophenone Promoted by Potassium Fluoride

An efficient method is reported for the synthesis of phenacyl esters by reaction of carboxylic acids with a-bromoacetophenone promoted by potassium fluoride in ionic liquid [Bmim]PF6, the yield of the reaction is almost quantitative and the products are essentially pure.