2001 Volume 12 Issue 3

First Enantioselective Synthesis of (2R, 3R)-and (2S, 3S)-2-(4-hydroxyphenyl)-3-hydroxymethyl-1, 4-benzodioxan-6-carbaldehyde
Wen Xin GU , Xiao Bi JING , Xiao Chuan CHEN , Xin Fu PAN
2001, 12(3): 189-192
[Abstract](158) [FullText HTML] [PDF 28KB](0)
A novel enantioselective synthetic approach to 1,4-benzodioxane lignans was reported in which (2R, 3R)-and (2S, 3S)-2-(4-hydroxyphenyl)-3-hydroxymethyl-1, 4-benzodioxan-6-carbaldehyde were first synthesized.
Synthesis of 2-Substituted Hexahydro-1H-1,4-diazepine Analogues
Jing Shan SHEN , Li Jun LEI , Tie Ma YAN , Jian Feng LI , Hui Jun LI , Zhen Hua LI , Ru Yun JI
2001, 12(3): 193-194
[Abstract](168) [FullText HTML] [PDF 26KB](0)
2-substituted hexahydro-1H-1,4-diazepine analogues were synthesized starting from N,N-dibenzyl-1,3-propylene diamine and methyl-2,3-dibromo propionate through nucleophilic substitution, reduction, chlorination and debenzylation.
A Case of Abnormal Bishler-Napieralski Cyclization Reaction, Leading to Form Benzyl Oxazole Derivatives
Zhan Zhu LIU , Shi Zhi CHEN
2001, 12(3): 195-196
[Abstract](179) [FullText HTML] [PDF 23KB](1)
A benzyl oxazole compound 3 was obtained with an excellent yield of 90% when Nacetyl-(2'-methoxy-4',5'-methylenedioxy)-phenylalanine methyl ester 1 was refluxed in POCl3/benzene. However, the anticipated product 3,4-dihydroisoquinoline-3-carboxylic acid methyl ester 2 could not be found. The mechanism was discussed in this article.
An Improved Method of Total Synthesis of 2-Methoxypodocarpane-8,11,13-triene
Qiang XIAO , Yu Xin CUI , Peng Fei TU
2001, 12(3): 197-198
[Abstract](152) [FullText HTML] [PDF 23KB](0)
12-Methoxypodocarpane-8,11,13-triene 1, the key intermediate in the synthesis of some important diterpenes, was synthesized in an efficient way, which has the characteristics of short route, simple operation and high yield.
Concise Synthesis of (±)-epi-Chrysotricine
Guang Xing WANG , Jing Xin ZHANG , Shu Feng CHEN , Xiao Tian LIANG
2001, 12(3): 199-202
[Abstract](148) [FullText HTML] [PDF 32KB](0)
(±)epi-Chrysotricine 6 was synthesized by a cascade stereoselective oxidative cyclization of 5-hydroxyalkene 3 using tert-butyl hydroperoxide (TBHP) catalyzed by VO(acac)2.
A Concise Approach to the Synthesis of Carnosic Acid Type Diterpenes
Yu Xin CUI , Qiang XIAO , Peng Fei TU
2001, 12(3): 203-204
[Abstract](169) [FullText HTML] [PDF 21KB](3)
10-vinyl-8,11,13-podocatriene 8, which is a model of Carnosic acid type diterpenes, has been synthesized by an expeditious convergent synthetic approach.
Chiral Synthesis of 13-Acetyl-12-hydroxy-podocarpane-8, 11,13-triene-7-one
An Pai LI , Yong Hong GAN , Xiao Shui PENG , Tong Xing WU , Xin Fu PAN
2001, 12(3): 205-206
[Abstract](160) [FullText HTML] [PDF 24KB](0)
An enantioselective synthetic route to (+)-13-acetyl-12-hydroxy-podocarpane-8,11,13-triene-7-one 1a and (-)-13-acetyl-12-hydroxy-podocarpane-8,11,13-triene-7-one 1b was developed from (S)-(-)-α-cyclocitral 8a and (R)-(+)-α-cyclocitral 8b.
A Novel Synthesis of Dimethyl Malonate by Carbonylation of Methyl Chloroacetate Catalyzed by Cobalt Complex
Wei Hong SONG , Xuan Zhen JIANG
2001, 12(3): 207-210
[Abstract](177) [FullText HTML] [PDF 32KB](1)
A novel method of preparing dimethyl malonate by carbonylation of methyl chloroacetate catalyzed by Na[Co(CO)4] was proposed. Na[Co(CO)4] was synthesized in situ in the presence of Na2S2O3 and iron powder. The effects of some reaction parameters such as temperature, CO pressure and the concentrations of catalyst on the yields of dimethyl malonate were discussed. The kinetic data were studied and a possible reaction mechanism was proposed.
Oxidative Degradation of 2,4,6-Trichlorophenol in the Presence of Air Ions
2001, 12(3): 211-214
[Abstract](160) [FullText HTML] [PDF 29KB](0)
2,4,6-trichlorophenol (TCP) was firstly treated with air ions generated by electric discharge, and high dechlorination (53%) was observed after 60 min treatment, indicating that air ions are an efficient dechlorination means and might have a future in the oxidative removal of chlorinated phenols. In addition, a stepwise degradation of TCP, beginning with the formation of a major product 2,6-dichloro-1,4-benzenediol via substitution, is proposed through a detailed analysis of gas chromatography/mass spectrometry.
Protonation and Dehydrogenation During the Multiphoton Ionization of the Cluster:C4H5N(H2O)n
Yong Jun HU , Yong CAI , Ri Chang LU , Nan Quan LOU , Xiu Yan WANG
2001, 12(3): 215-218
[Abstract](170) [FullText HTML] [PDF 58KB](1)
Multiphoton ionization (MPI) of the hydrogen-bonded clusters C4H5N-(H2O)m was studied with a time of flight (TOF) mass spectrometer at 355 nm. Series of the pyrrole-watercluster ions were observed, including unprotonated cluster ions[C4H5N-(H2O)n]+, protonated cluster ions[C4H5N-(H2O)nH]+ and dehydrogenated cluster ions[C4H4N-(H2O)n]+. Both the experimental and ab initio calculated results agree with that the dehydrogenation has more probabilities to occur while the value of n is raised.
On the Structure of the Arginine-carboxylate Salt Bridge:A Density Functional Theory Study
Ting Wei MU , Yong FENG , Lei LIU , Qing Xiang GUO
2001, 12(3): 219-222
[Abstract](176) [FullText HTML] [PDF 27KB](0)
High-level density functional theory (DFT) calculations are performed for the first time to answer the question whether the arginine-carboxylate salt bridge stays in a zwitterionic state or a neutral one. The results indicate that in the gas phase, the neutral form is more stable and hence proton transfer occurs from guanidinium to carboxylate. However, in an aqueous solution the zwitterionic form should be favored. The difference might be caused by the electrostatic interaction between the salt bridge and its molecular environment. Therefore, the solvation effect has to be considered in the modeling of proteins, whose stabilization depends heavily on the saltbridges.
Two-Parameter Stochastic Resonance in a Model of Electrodissolution of Fe in H2SO4
Zong Xin PI , Hou Wen XIN
2001, 12(3): 223-226
[Abstract](165) [FullText HTML] [PDF 42KB](0)
Stochastic resonance (SR) is shown in a two-parameter system, a model of electrodissolution of Fe in H2SO4. Modulation of two different parameters by a periodic signal in one parameter and noise in the other parameter is found to give rise to SR. The result indicates that the noise can enlarge a weak periodic signal and lead the system to order. The scenario and novel aspects of SR in this system are discussed.
Tsaokoin, a New Bicyclic Nonane from Amomum tsao-ko
Qi Shi SONG , Rong Wei TENG , Xi Kui LIU , Chong Ren YANG
2001, 12(3): 227-230
[Abstract](172) [FullText HTML] [PDF 32KB](0)
7α-Hydroxy-8β,9β-H-cis-bicyclo[4,3,0]non-4-ene-4-aldehyde, a nonane compound with novel skeleton, named tsaokoin, was isolated from the fruits of Amomum tsao-ko. Its structure was established on the basis of spectral analysis.
A New Flavone Glycoside from Isodon enanderianus
Zhi NA , Shuang Xi MEI , Chao Ming LI , Zhong Wen LIN , Han Dong SUN
2001, 12(3): 231-232
[Abstract](168) [FullText HTML] [PDF 24KB](2)
A new flavone glycoside, 5,8-dihydroxy-4',6,7-trimethoxyflavone 8-O-β-Dglucopyranoside 1, together with three known flavonoids, pedalitin 2, cirsimartin 3 and genkwanin 4, were isolated from the aerial parts of Isodon enanderianus. Their structures were determined on the basis of spectral data.
A New Flavanone from the Bark of Morus macoura Miq.
Sheng Guo SUN , Ruo Yun CHEN , De Quan YU
2001, 12(3): 233-234
[Abstract](171) [FullText HTML] [PDF 29KB](1)
A new flavanone named macrouroine C (1) was isolated from the bark of Morus macroura Miq.. The structure of 1 was elucidated mainly on the basis of spectroscopic evidence.
Novel Chromone Derivatives from Marine Fungus Aspergillus versicolor Isolated from the Sponge Xestospongia exigua
Wen Han LIN , Hong Zheng FU , Jun LI , Peter Proksch
2001, 12(3): 235-238
[Abstract](173) [FullText HTML] [PDF 34KB](0)
From the marine sponge Xestospongia exigua, fungal isolates of Aspergillus versicolor (Vuill) Triab were obtained. Isolation and purification of ethyl acetate extracts from culture filtrates of the fungus led to yield six new chromone derivatives namely aspergione A, aspergione B, aspergione C, aspergione D, aspergione E, aspergione F. The structures of all the new compounds were established on the bas is of extensive spectroscopy (UV, MS, 1H and 13C NMR, COSY, HMQC and HMBC) analysis.
Two New Dammarane Glycosides from the Acid Hydrolysis Product of Panax Notoginseng
Rong Wei TENG , Hai Zhou LI , Xue Mei ZHANG , Xi Kui LIU , De Zu WANG , Chong Ren YANG
2001, 12(3): 239-242
[Abstract](171) [FullText HTML] [PDF 35KB](0)
Two new dammarane glycosides named notoginsenoside T1 and T2 were isolated from the mild acid hydrolysis products of the root saponins of Panax notoginseng. On the basis of spectroscopic evidences, their structures were elucidated to be 6-O-β-D-glucopyranosyl-24(25)-epoxy-3β,6α,12β,23 ζ-tetrahydroxydammar-20(22)(E)-ene 1 and 6-O-β-D-glucopyranosyl-24(25)-epoxy-23 ζ-methoxyl-3β,6α,12β-trihydroxydamm-ar-20(22)(E)-ene 2, respectively.
A New Indole Alkaloid from Limonia Crenulata
Xue Mei NIU , Sheng Hong LI , Li Yan PENG , Gao Xiong RAO , Han Dong SUN
2001, 12(3): 243-244
[Abstract](170) [FullText HTML] [PDF 20KB](0)
A new indole alkaloid, crenulatine 1, was isolated from the stems of Limonia Crenulata. The structure was identified by spectral means.
A Novel Ursane Triterpene from Rubus swinhoei
Wei Quan ZHAO , Li Sheng DING , Qiang ZHANG , Ming Kui WANG
2001, 12(3): 245-246
[Abstract](182) [FullText HTML] [PDF 25KB](2)
A novel ursane triterpene, named swinhoeic acid, was isolated from the roots of Rubus swinhoei. Its structure was elucidated as 18, 19-seco, 2α, 3β-dihydroxy-19-oxo-urs-11, 13(18)-dien-28-oic acid by means of MS, 1DNMR and 2DNMR.
A New Norditerpene from Miliusa balansae Finet et Gagnep
Rui WU , Qi YE , Neng Yu CHEN , Guo Lin ZHANG
2001, 12(3): 247-248
[Abstract](169) [FullText HTML] [PDF 28KB](0)
A novel norditerpene, miliusate (1), was isolated from Miliusa balansae Finet et Gagnep. Its structure was elucidated by spectral analysis.
A Novel Catalyst for CO2 Reforming of CH4
Chuan Jing HUANG , Xiao Ming ZHENG , Liu Ye MO , Jin Hua FEI
2001, 12(3): 249-252
[Abstract](172) [FullText HTML] [PDF 47KB](0)
A novel Ni-Co/SiO2 catalyst which exhibits high activity and excellent anti-carbon deposition property for CO2 reforming of CH4 to synthesis gas is developed.
Sol-Gel Method for Preparation of LiLaNiO/γ-Al2O3 Catalyst over Monoliths used in POM Reaction
Ran RAN , Guo Xing XIONG , Yu Hong ZHANG , Shi Shan SHENG , Wei Shen YANG
2001, 12(3): 253-256
[Abstract](167) [FullText HTML] [PDF 53KB](0)
A new method for preparing LiLaNiO/γ-Al2O3 monolithic catalyst was described and discussed. The catalyst, which was supported over the monolith, was evaluated in a POM to syngas process. Relative stable catalytic properties during the 120 hours operation at atmospheric pressure were found for the catalyst. Under the high space velocity of 9.0×104l/(kg·h)(CH4), the conversion of methane came to 95.5%, and the selectivity of carbon monoxide was not below 96.0% at 1123K when ratio of the feedstock (CH4/O2) was equal to 2.0.
A New Type of Polymer-Supported Metallocene Catalyst for Ethylene Polymerization
Guang Qian YU , De Ze ZHANG , Fu SHUN , Li Jun QIAO , Tao TANG , Bao Tong HUANG
2001, 12(3): 257-260
[Abstract](175) [FullText HTML] [PDF 42KB](0)
A new polymer-supported metallocene catalyst has been prepared. The polymersupported metallocene displayed considerably high activity in ethylene polymerization,the highest being 3.62×107gPE/molZr·h, the molecular weight of the polyethylene produced was Mn=1.29×105, about 3-4 times those of corresponding homogeneous zirconocenes. The polymersupported metallocene keeps the characteristics of homogeneous metallocene catalysts, and offers some features,such as adaptable to gas phase and slurry processes; easy to prepare in low cost; relatively high activity and lower MAO/Zr ratio; lower inorganic residues in the polyolefins as compared to cases of SiO2,Al2O3 or MgCl2; unitary active structure, no complex surface as with SiO2; good control of morphology of the resulting polymer.
A New Rapid Determination Method of Soil Organic Carbon Adsorption Coefficients of Pesticides with Soil Column Liquid Chromatography
Wei Min WANG , Xin Miao LIANG , Qing ZHANG
2001, 12(3): 261-264
[Abstract](167) [FullText HTML] [PDF 33KB](0)
Soil column liquid chromatography (SCLC) was developed to determine soil organic carbon adsorption coefficients (Koc) for chemicals. The uptake by soil of pesticides from water can be conveniently calculated from the related breakthrough curves (BTC). The nine pesticides chosen for determination in this study are soluble ones, with their water solubility ranging from 62 mg/L to 2 mg/L. In comparing with existing methods of Koc, SCLC possesses rapid, online and accurate characteristics.
On-Line Multichannel Raman Spectroscopic Detection System For Capillary Zone Electrophoresis
Zhong LI , Yu Jie WANG , Guo Quan LIU , Yi CHEN
2001, 12(3): 265-266
[Abstract](160) [FullText HTML] [PDF 31KB](0)
An on-line multichannel Raman spectroscopic detection system for capillary electrophoresis was established by using an Ar+ laser and a cryogenically cooled ICCD. Resonant excitation Raman spectra of methyl red and methyl orange were employed to test the system. The result shows that it could yield on-line electrophoretogram and time series of Raman spectra.
A New Chemiluminescent Triazine Reagent
Quan Li MA , Mei Hong SU , Hui Min MA , Zhi Hua WANG , Shu Chuan LIANG
2001, 12(3): 267-268
[Abstract](179) [FullText HTML] [PDF 18KB](0)
A new chemiluminescent reagent 7-(4,6-dichloro-1,3,5-triazinylamino)-4-methylcoumarin (DTMC) was synthesized by linking 7-amino-4-methylcoumarin to cyanuric chloride at 0-5℃, and with it a novel chemiluminescence method was developed for the determination of hydrogen peroxide. The selectivity of this method is high, and most of the transition metal ions have no effect on the determination of H2O2.
Electrochemistry and Electrocatalysis with Hemoglobin in DHPPDDA Surfactant-Polymer Multibilayer Composite Films
Nai Fei HU , Hong Yun LIU , Li Wen WANG
2001, 12(3): 269-270
[Abstract](165) [FullText HTML] [PDF 21KB](0)
Polyionic complex DHP-PDDA was prepared by reacting anionic surfactant dihexadecyl phosphate (DHP) with polycationic poly(diallyldimethyl ammonium) (PDDA). Thin films made from DHP-PDDA with incorporated hemoglobin (Hb) on pyrolytic graphite (PG) electrodes were characterized by electrochemistry and other techniques.
The Aggregates in LB Films of Schiff base Aluminium (III) Complex
Wei CAO , Wei LIAN , Yu Bai BAI , Chun Yan LIU , Hui Bo SHAO
2001, 12(3): 271-272
[Abstract](175) [FullText HTML] [PDF 31KB](0)
The surface pressure-area (π-A) isotherm of Schiff base aluminium (III), tris (2-hydroxy-5-nitro-N-dodecyl-benzylideneaminato) aluminium (III) (denoted as Al(TA12)3), on pure water subphase was investigated. The molecular area, 0.48 nm2, is one-third of expected value that indicated the aggregation took place. The Langmuir-Blodgett (LB) films of Al(TA12)3 was transferred and characterized. The AFM image confirmed the formation of aggregates.
Dynamic Rheological Characterization of A Thermotropic Liquid Crystalline Poly (aryl ether ketone)
Hui SUN , Wan Jin ZHANG , Zhong Wen WU , Li Wei LI , Bi Bo YANG , Qiang ZHENG
2001, 12(3): 273-274
[Abstract](173) [FullText HTML] [PDF 39KB](0)
The rheometrics ARES rheometer was applied to determining the rheological behavior of a thermotropic liquid crystalline poly (aryl ether ketone). The viscosity of the material decreases with increasing temperature, reaching a minimum in the nematic state, then slightly increases with further raising the temperature in the biphase.
A New Method to Remove Neutral Template in the Synthesis of HMS
Qing Min ZHANG , Yan LI , Fu Zhi HUANG , Zhen Nan GU
2001, 12(3): 275-278
[Abstract](180) [FullText HTML] [PDF 146KB](0)
In the synthesis of HMS, Soxhlet extraction as a new method to remove neutral template was studied. HREM image, X-ray diffraction patterns and nitrogen adsorption-desorption results verified that this method can not only efficiently remove and recoverthe template, but also benefit the maintenance of the mesoporous framework structure.
Synthesis, Structure and Properties of Tetrakis (thiourea) mercury (II) Tetrakis (thiocyanato-N) zinc (II)
Xue Ning JIANG , Dong XU , Duo Rong YUAN , Wen Tao YU , Meng Kai LU , Shi Yi GUO , Guang Hui ZHANG , Qi FANG
2001, 12(3): 279-282
[Abstract](164) [FullText HTML] [PDF 57KB](0)
A new nonlinear optical complex crystal tetrakis (thiourea) mercury (II) tetrakis (thiocyanato-N) zinc (II) was synthesized and its structure was determined. It belongs to the tetragonal system, I4 space group. The crystal structure consists of discrete[Zn(SCN)4]2- anions and[Hg(NH2CSNH2)4]2+ cations with slightly distorted coordination tetrahedra ZnN4 and HgS4. The second harmonic generation (SHG) of the crystal was found to be superior to that of urea.
Address:Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888
Powered By info@rhhz.net