中国化学快报

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PALLADIUM CATALYZED REACTION OF 3-TRIMETHYLSILYLPROPARGYLIC CARBONATES WITH DINUCLEOPHILES

Li Ferg GENG, Xi Yan LU

中国化学快报. 1991, 2(08): 595-596.

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Methyl 3-trimethylsilylpropargyl carbonate reacted with dinucleophiles under the catalysis of palladium(0) complex to give the corresponding desilylated annulation products.

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PENTAFLUOROBENZENESULFONYL BROMIDE AND ITS REACTIONS

Qing Yun CHEN, Ming Fang CHEN

中国化学快报. 1991, 2(08): 597-600.

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Pentafluorobenzenesulfonyl bromide was synthesized by the reaction of pentafluorophenylmagnesium chloride with sulphur dioxide followed by bromine oxidation. The sulfonyl bromide reacted with polyfluorophenoxide to form polyfluorophenyl pentafluorobenzenesulfonates. Photolysis of pentafluorobenzenesulfonyl bromide gave bis(pentafluorobenzene)sulfone and decafluorodiphenyl.

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SYNTHESIS OF 6-AMINO, 6-METHOXY AND 6-ETHOXY PURINENUCLEOSIDE DERIVATIVES

Li Ya ZHU, Xiao Tian LIANG, Tai Shun LIN

中国化学快报. 1991, 2(08): 601-604.

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A convenient route for the conversion of inosine to the corresponding 6-amino, 6-methoxy and 6-ethoxy derivatives is reported. This conversion can be achieved by ammoniation or etherification of the 6-pyridinium intermediate(3) which can be readily produced under mild reaction conditions. The chemistry and characterization of these compounds are presented, A plausible mechanism of the reaction is proposed.

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STUDIES ON SULFINATODEHALOGENATION A NEW REACTION OF SODIUM DISULFITE

Bing Nan Huang, Fan Hong Wu

中国化学快报. 1991, 2(08): 605-606.

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the utility of sodium disulfite as a new sulfinatodehalogenation reagent for primary polyfluoroalkyl iodides and bromides is reallzed.

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The Synthesis of Polyfluoroalkylbiphenyl

Wei Yuan HUANG, Wei Wen YING

中国化学快报. 1991, 2(08): 607-608.

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Polyfluoroalkylated biphenyl was obtained from reaction of benzene with R_FI/Na₂S₂O₄ using cetyltrimethylammonium bromide (CTAB) as PTC followed by dehydrogenation with DDQ in 38-43% yield.

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THE UNUSUAL REDUCTION OF SOME AROMATIC ALDEHYDES BY SODIUM BOROHYDRIDE

Hong Bin ZHOU, Xin De FNEG, Qi Feng ZHOU

中国化学快报. 1991, 2(08): 609-610.

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Two aromatic aldehydes are found to be reduced by an unusual way by sodium borohydride in the presence of water to yield the corresponding methyl substituted aryl compounds.

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MODIFICATION OF WOLINSKY'S ENE-CHLORINATION

He Sheng ZHANG, Jia Wei CHEN

中国化学快报. 1991, 2(08): 611-612.

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Ene-chtorination of the otefins bearing isopropenyl moieties has been achieved in good yieid by using catcium hypochiorite and sodium biphosphate. An efficient synthesis of San Jose ScaLe's sex pheromone is described.

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A NOVEL DEHYDROGENATION REACTION UNDER SINGLET OXYGENATION CONDITION

Hiu Kwong LEUNG, Yong Yue LIN, Zhi Ming LIN

中国化学快报. 1991, 2(08): 613-616.

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1-Aryl-2-merhy1-4, 5-dihydropyrro1-3-carboxylic acid ethyl ester was observed to dehydrogenate to give 1-ary1-2-methyl-pyrro1-3-carboxylic acid ethyl ester upon irradiation in the presence of oxygen and in the presence or absence of ms-tetraphenylporphine.

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FUNCTIONALIZED CYCLODEXSTRINS BEARING AMINOALKYLIMINO GROUPS AS ACTIVE CENTERS TO CATALYZE ALDOL CONDENSATIONS

De Qi YUAN, Ru Gang XIE, Hua Ming ZHAO

中国化学快报. 1991, 2(08): 617-620.

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Efficient catalysis of functinnatized β-cyctodextrins bearing aninoatkytimino groups for atdot condensations of nitrobenzatdehydes and acetone has been effected and substantiated by preparative experiments

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A NEW DOLASTANE DITERPENE PROM DICTYOTA DIVARICATA

Lian Niang LI, Qiao Hong DENG

中国化学快报. 1991, 2(08): 621-622.

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Deacetylamijidictyol, a new dolastane diterpene was isolated from the marine brown algae Dictyota divaricata. The chemical structure was elucidated on the basis of spectral analysis.

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NEOLIGNANS FROM PIPER KADSURA

Ying MA, Gui Qiu HAN, Cun Heng HE, Qi Tai ZHENG

中国化学快报. 1991, 2(08): 623-626.

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Two new neolignans, Kadsuranin G and Kadsuranin H, were isolated from Piper Kadsura (Choisy) Ohwj. Baaed on the spectroscopic analysis (UV, IR, MS, NNR, and X-ray) and chemical reactions, their structures were established as 7R, BR, 1'S, 2'R, 3'5-△^8'-3, 4, 5'-trimethoxy-2'-hydroxy-1', 2', 3', 4'-tetrahydro-4'-oxo-7, 3', 8, 1'-neolignan and 7R, 8R, 1'S, 2'R, 3'S-△^8'-3, 4, 5'-trimethoxy-2'-acetyloxy-1', 2', 3', 4'-tetrahydro-4'-oxo-7, 3', 8, 1'-neolignan.

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ISOLATION, PROPERTIES AND CHEMICAL STRUCTURE OF À GLUCAN FROM GLYCYRRHIZIA URALENSIS FISCH

Ji Nian FANG, Bin Can LIN

中国化学快报. 1991, 2(08): 627-628.

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A new polysaccharide, GBW was obtained homogeneous as determined by HPLC from the roots of Glycyrrhizia uralensis Fisch. The molecular weight was estimated to be 4000. The component sugar was identified as glucose only. The specific rotation [α]_D²⁸ (C=0.1, H₂O) was +120⁰. The α-configuration was established by IR and ¹³C NMR. Methylation analysis, periodate oxidation, Smith degradation, partial hydrolysis, KI-I₂ reaction and ¹³C NMR showed that GBW is a new (1→4)linked linear α-D-glucan. The structure is shown as 1.

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ISOLATION, STRUCTURE ELUCIDATION AND SYNTHESIS OF À NEW PRENYLATED FLAVONOL, MAACKIAFLAVONOL, FROM MAACKIA TENUIFOLIA

Jian Hua SHEN, Lan WANG, Bing Nan ZHOU

中国化学快报. 1991, 2(08): 629-630.

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À new prenylated flavonol, maackiaflavonol, was isolated from the ethanol extract of the roots of Maackia tenuifolia. Its structure was elucidated as 7-hydrox-8-prenylflavonol by means of spectroscopic analysis (UV, IR, MS, NMR and ¹H-¹H COSY) and confirmed by total synthesis.

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THE NEGATIVE-ION CHEMICAL-IONIZATION MASS SPECTRA OF SOME 2, 6, 7-TRIOXA-1-PHOSPHABICYCLO[2.2.2]OCTANE-1-OXIDE DERIVATIVES

Jie You XUE, Da Zhi TANG, Rui Lian SHAO, Shi Xiong TANG

中国化学快报. 1991, 2(08): 631-632.

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The metaphosphate anion, PO₃^-, was detected in the negative-ion chemicalionization mass spectra of 2, 6, 7-trioxa-1-phospbabicyclo[2.2.2] octane-1-oxides.

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STUDY ON ENRICHMENT AND SEPARATION OF TRACE ELEMENTS WITH SILICA GELS MODIFIED BY HETEROCYCLIC AZO DYES

Ke An LI, Feng LIU, Shen Yang TONG

中国化学快报. 1991, 2(08): 633-636.

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Two types of modified silica gels were prepared by adsorption method and bonding method respectively. Enrichment and separation of trace metal ions have been done by using the column packed with modified silica gels.

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INTERSECTION POINT RULE OF THE RETENTION VALUE AND NORMAL BOILING POINT OF THE HOMOLOGUES IN REVERSED-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

Fu An WANG, Chang Sheng YANG, Wen Chang WANG, Yuan Li JIANG

中国化学快报. 1991, 2(08): 637-640.

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In this paper, a linear relationship between the logarithm of capacity factor k' and normal boiling point to of the homologues has been derived, based on the basic retention equation of liquid chromatography according to statistical thermodyoamics proposed by professor Ln Peizhang and others, This equation has been verified by a large number of experimental data, all the strsight lines of lnk'--t_b of bumologues for different mobile phass coaiposltion cross each other at the same point, So the intereection point equation was proposed, wbich was used to prodict the retention value, the result was satisfactory.

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KINETIC AND APPLICATION: STUDIES ON THE REACTION SYSTEM OF OSMIUM(Ⅳ)-ARSENIC(Ⅲ)-CHLORATE

Chen Zhen QIN, Xiao Jin LI, Zhi Liang JIANG

中国化学快报. 1991, 2(08): 641-644.

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The experiments have proved that Os(Ⅳ) has very strong catalytic effect on the chlorate oxidation of As(Ⅲ) in perchloric acid media, and As(Ⅲ) exhibits a sensitive single-sweep oscillopolarographic wave at-0.75 V vs. SCE. The kinetics of this catalytic reaction has been investigated by the initial rate procedure. The mechanism has been proposed. A new and highly sensitive catalytic reaction-oscillopolarographic method for the determination of ultratrace amounts of osmium has been described, based on the Os(Ⅳ) catalytic effect on the reaction. The linear range of 5.0×10^-11-4.4×10^-9 mol/L and 6.0×10^-9-1.3×10^-7 mol/L Os was obtained using the fixed-time procedure and the initial rate procedure, respectively. Osmium in refined ore was analysed by this method.

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SIMULTANEOUS DETERMINATION OF VITAMIN B COMPLEX (THIAMINE, RIBOFLAVIN, NIACIN, PYRIDOXINE AND FOLIC ACID) IN FOODS BY HPLC

Ya Shan HAN, Xiao Qing SONG, Jin Cheng ZHAO, Yun Qing DAI

中国化学快报. 1991, 2(08): 645-648.

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A high performance liquid chromatographic assay has been developed for the simultaneous determination of five water soluble vitamins:thimine, riboflavin, niacin, pyridoxine and folic acid in cereal products and fresh vegetables. Food samples were hydrolyzed in 0.4 mol/L HCl, autoclaved at 120℃ 15 psi for 20 minutes, using a μ-Bondapak column (3.9×300mm, Waters Co.), a mobile phase of methanol-water (30:70) (0.005 mol/L heptanesulfonic acid) and a flow rate of 1.0 ml/min gave the most satisfactory separation of the five water soluble vitamins. A double channel deteetion was used: four vitamins (B₅, folic acid, B₂, B₁) were detected hy UV spectrophotometry (254 nm) first, pyridoxine (B₆) was detected by fluoromelry (EX 290nm, EM 395 nm) afterwards. Detection limits were 2, 5, 5, 2 and 5ng, linear ranges were 5-10ng, 5-50ng, 5-40ng, 5-50ng and 10-50ng for B₁, B₂, B₅, B₆ and folic acid respectively. Recoveries were 92-100%(B₅), 51-52% (folic acid), 103-105% (B₂), 99-100% (B₆) and 91.3-102% (B₁) respectively. In comparison with a reference method and checking with food composition tables, very satisfactory results were obtained by this method.

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SIMULTANEOUS DETERMINATION OF FAT SOLUBLE VITAMINS A, D₃, E AND K₁ IN FORTIFIED MILK POWDERS BY HPLC

Ya Shan HAN, Yun Qing DAI

中国化学快报. 1991, 2(08): 649-652.

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A high performance liquid chromatographic method for the simultaneous determination of four fat soluble vitamins: retinol (vitamin A), cholecalciferol(vitamin D), tocopherol(vitamin E) and phylloquinone(vitamin K₁) in fortified milk powders and egg yolk has been developed. The method requires enzymatic hydrolysis of lipid component of the sample as a pretreatment. Several factors which influence the enzymatic hydrolysis were studied-Separation was achieved using μ-Bondapak C-18 column(3.9×300mm), 98% methanol as mobile phase, a double channel detection was selected; vitamins D₃ E₁ K₁ were detected by UV spectrophotometry (265 nm) first, then vitamin A by fluorometry (EX 325nm, EM 480nm). The retention times of vitamin A₁ D₃, E and K₁ 4.87, 9.00, 10.58 and 15.45 min respectively. Detection limit were 0.64, 0.25, 0.50 and 0.07 ng; and the recoveries were 90.5%~103.6%, 90.0%~95.6%, 91.7%~98.8%, 91.5%~98.6%, respectively. The vitamins A, D₃, E, K₁ contents in foods were determined satisfactorily.

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The Triangle-relationship of β-lactam Antitiotics

Jing Jiang LIU, Ji Wei TANG, Min Hui ZHU, Xiao Ling FAN

中国化学快报. 1991, 2(08): 653-654.

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The geometric parameters for D-Ala-D-Ala are optimized by MM, the most and next two stable conformations are obtained. According to the interaction model with target emzyme suggested by us, the traingle-relationship of it is obtained. This triangle-relationship could be found in the pharmaceuticals belong to different classes of β-actams also.

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THE EFFECTS OF SOLVENTS ON THE INTRAMOLECULAR PROCESSES------NMR STUDY

Rui Fang SONG, Cun Zhi ZHANG, Fei LI

中国化学快报. 1991, 2(08): 655-656.

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The influences of methanol-d₄(MeOD), dimethylsulfoxide-d₆ (Me₂SO(D)) and dioxane(C₄H₈O₂) solvents on the intramolecular processes are studied by NMR. It has been shown that the addition of these solvents in CdEGTA complex aqueous solution can increase the rate constant (k) of the nitrogen inversion and decrease the activation energy of this process. The linear relations between In(k) and the reciprocal of the solvent dielectric constants (1/ε) are obtained for all the three solvents.

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CARBONACEOUS PRODUCTS OF POLYMER-PALLADIUM COMPLEXES AS CATALYSTS FOR THE HYDROGENATION OF METHYL ACRYLATE

Chun Fu CHEN, Jun Tan SUN, Hong Li, Bing Lin HE, Xian Quan GUO, Xiu Ping SHI

中国化学快报. 1991, 2(08): 657-658.

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Many catalysts were pcrpared by carbonization of ion exchange resin-PdCl₂ complexes at high temperature in nitrogen, hydrogen atmosphere. The rates for the hydrogenation of methyl acrylate and the amounts of Pd elution of the carbonaceous products were measured and compared with those of commercial Pd/C catalyst. It indicates that the carbonaceous products are less active than Pd/C. However, the leaching of Pd from carbonaceous products is very small and much less than that from Pd/C.

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LIQUID CRYSTAL POLYMERS WITH TWO-DIMENSIONAL MESOGENIC UNITS

Qi Feng ZHOU, Zhi Cai WU, Robert W. LENZ

中国化学快报. 1991, 2(08): 659-660.

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A series of "liquid crystal polymers with two-dimensional mesogeuic units" were synthesized by the polycondensations of the monomer 2, 5-dihydroxybenzylidene-4-phenetidine with a diacid chloride selected from a series of α, ω-bis(4-chloroformylphenyloxy)carbonylalkues. This is the first series of polymers reported under the newly proposed concept "liquid crystal polymers with two dimensional mesogenic units".

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A STUDY OF STRUCTURE TRANSITION OF CHLORIDE LAYER ADSORBED ON Ag(100) ELECTRODES

Bing Wei MAO

中国化学快报. 1991, 2(08): 661-664.

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The behavior of chloride adsorbed on Ag(100) electrode has been studied using chronoamperometric technique, and the structural transition of chloride layer has been confirmed.

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SYNTHESIS AND PROPERTIES OF POTASSIUM 11-TUNGSTONIOBATE

You Cai ZHAO, Yi Dong GU

中国化学快报. 1991, 2(08): 665-668.

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The anion of tungstoniobate was synthesized for the first time as KqNbW″O₄₀ 2H₂O by the reaction of soluble potassium niobate and porous white tungstic acid in aqueous solution. The structure of the anion may be proposed reasonably to be similar to that of dodecameric anion of paratungstate, resulting from substituting of one WO₆ group in paratungstate anion by one NbO₄ group and leading to the formation of tungstoniobate anion according to the extreme similarity of IR and UV spectra of these two different anions. Potassium 11-tungstoniobate is soluble in wator and unstable in alkaline medium while the structure of the anion may be considered to keep unchanged in acidic medium according to the spectrophotometrical results.

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STUDY ON THE COORDINATION COMPOUNDS OF RARE EARTHS WITH DIPEPTIDE-COORDINATION OF RARE EARTHS WITH DL-ALANYL-ALANINE

Jian Xue LIU, Qing Bo MENG, Chun Ji NIU, Jia Zuan NI

中国化学快报. 1991, 2(08): 669-672.

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In this paper protonation constants of the title lisand and stability constants of its coordination compounds with rare earths have been determined by potentiometric titration at 25±；0.1℃ and ionic strength of 0.10mol.dm^-3 NaClO₄. The coordination of rare earths with DL-alanyl-alanine has been discussed. The stability of the coordination compound shows "tetrad effect". The position for yttrium shifts from its usual Bo-Er region to the vicinity of Tb.

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1991年, 第2卷, 第08期　刊出日期：1991-08-20

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1991年, 第2卷, 第08期 刊出日期：1991-08-20

1991年, 第2卷, 第08期　刊出日期：1991-08-20