1998 Volume 9 Issue 10

Samarium Diiodide-Induced Reductive Cleavage of Se-St Bond in Arylselenotrimethylsilane Leading to the Formation of Samarium Arylselenolate:Synthesis of β-Arylseleno Estsrs and β-Arylseleno Nitriles
Song Lin ZHANG , Yong Min ZHANG
1998, 9(10): 885-887
[Abstract](191) [FullText HTML] [PDF 117KB](0)
Abstract:
The Se-Si bond in arylselenotrimethylsilane was reduced by samarium diiodide to produce samarium arylselenolate, which reacted with α,β-unsaturated esters or α,β-unsaturated nitriles to give β-selenoesters and β-selenonitriles, respectively.
Stereoselective Addition of Organotitanium and Grignard Reagents to 3,5-O-isopropylidene-L-glucurono-γ-lactone
Hong CHEN , Shao Yi SUN , De Quan YU
1998, 9(10): 889-892
[Abstract](280) [FullText HTML] [PDF 118KB](0)
Abstract:
Substituted PhMgX and PhTi (OCHMe2)4MgX react with 3,5-O-isopropylidene-L-glucurono-γ-lactone 4 to give tetraols 5a~e and its stereoisomers 6a~e. Tetraols 5a~e are the important intermediates in the synthesis of howiinol A1 and its derivatives. The stereoselectivities of substituted PhTi (OCHMe2)4Mg (5a~e:6a~e ratio, 68~72:32~28) were better than those of substituted PhMgX (33~64:67~36) in the reaction. The effects of different substituted groups and positions (p-Me, m-Me, o-MeO, p-Cl) of the phenyl ring on their stereoselectivies were not significant.
Synthesis of a New Aryl Ether Ketone Polymer
Zhao Bin QIU , Zhi Shen MO , Hong Fang ZHANG
1998, 9(10): 893-894
[Abstract](202) [FullText HTML] [PDF 83KB](0)
Abstract:
The synthesis of a new aryl ether ketone polymer with an advantageous ratio of glass transition temperature to melting temperature is reported.
Trapping of the Dichlorocarbene Intermediate in the Reactionof α-Cyanobenzyl carbanion with Carbon Tetrachloride
Jin Pei CHENG , Zi Rong ZHENG
1998, 9(10): 895-896
[Abstract](261) [FullText HTML] [PDF 91KB](0)
Abstract:
In Me2SO, an X-philic reaction took place between α-cyanobenzyl carbanion and CCl4. The intermediate dichlorocarbene was trapped by the primary product dicyanostilbene to give the alkene-carbene adduct, 1,l-dichloro-2,3-dicyano-2,3-diphenylcyclopropane.
Study on the Thermodynamic Stabilities of Te-Substituted Di-n-butyltellurium Ylide
Bo LIU , Jin Pei CHENG , Chi Zhong XIA
1998, 9(10): 897-898
[Abstract](202) [FullText HTML] [PDF 95KB](1)
Abstract:
Eight Te-substituted di-n-butyltellurium bromides were synthesized. Their equilibrium acidities (pKA) were determined in DMSO at 25℃ and the thermodynamic stabilities of the corresponding tellurium ylide carbanions were accordingly discussed.
Further Report on A Novel Scission of Alkyl Carbonyl C-C Bond by Substituted 4-Hydroxyacetophenones
Jiang WANG , Hui Tong TANG , Pang ZHANG , Thomas C. W. MAK , Ze Ying ZHANG
1998, 9(10): 899-902
[Abstract](208) [FullText HTML] [PDF 99KB](1)
Abstract:
3-Methoxy-,3, 5-dimethoxy-, and 3-pheny 1-4-hydroxyacetophenones suffered alkyl carbonyl C-C bond scission to yield 4-hydroxybenzoate esters and 4-isopropenylphenols under standard conditions of ethylene ketal formation; the latter underwent in situ dimerization, cyclization, and rearrangement to give substituted indanols. The isopropenylphenol derived from 3,5-ditertbuty 1-4-hydroxyacetophenone did not dimerize but condensed with its precursor to yield a substituted diphenylpropanone. 3-nitro-, 3,5-dinitro-, and 3,5-dibromo-4-hydroxyacetophenones on the other hand reacted normally to give ethylene ketals in good yields.
The Isomerization/Chlorination of O,O-D iallyl Thiophosphoric (-nic) Acid Esters with Phosphorus Oxychloride——A New Convenient Method for Synthesis of S-Alkyl Thiophosphoric(-nic) Acid Derivatives
Zheng Jie HE , Ju Xiang LIU , Zheng Hong ZHOU , Chu Chi TANG
1998, 9(10): 903-905
[Abstract](192) [FullText HTML] [PDF 84KB](0)
Abstract:
The isomerization/chlorination of 0,0-diallyl thiophosphoric(-nic) acid esters with phosphrus oxychloride gives S-allyl thiophosphoro(-no)chloride, which reacts with substituted phenol in chloroform in the presence of triethylamine to afford eighteen new S-allyl thiophosphoric(-nic) acid derivatives. Thus, a new convenient method has been provided for synthesis of the title compounds.
Unexpected Formation of Optically Active Monofluorine-Containing Bicyclic Compounds
Feng Ling QING , Sheng PENG
1998, 9(10): 907-910
[Abstract](191) [FullText HTML] [PDF 122KB](0)
Abstract:
New optically active bicyclic compounds containing a fluorine atom (3a and 3b) were prepared from the reaction of Garner aldehyde 1 with DAST.
Synthesis and Luminescent Properties of Eu3+-doped Na24P2W22O83
Shui Jin YANG , Ju Tang SUN , Zi Bin QIN
1998, 9(10): 911-912
[Abstract](180) [FullText HTML] [PDF 95KB](0)
Abstract:
The Eu3+-doped Na24P2W22O83 has been prepared by solid state reaction, and characterized by element analysis, infrared spectroscopy, powder X-ray diffractometry. The emission and excitation spectra were measured. The luminescence properties of Eu3+-doped Na24P2W22O83 and the energy transfer mechanism were discussed.
Squarylium Cyanine Dyes for Photoelectric Conversion
Wei ZHAO , Bac Wen ZHANG , Yi CAO , Xu Rut XIAO
1998, 9(10): 913-916
[Abstract](177) [FullText HTML] [PDF 143KB](0)
Abstract:
Two squarylium cyanine dyes (Sqs) were synthesized to explore their applications in photoelectrochemical solar cells. Nanocrystalline Ti02 electrodes modified with Sqs have been prepared to probe the photosensitization effects. A rather high photoelectric conversion efficiency of up to 2.17% and the top incident monochromatic photon-to-photocurrent conversion efficiency (IPCE) of 6.2% at 650nm were obtained from the Sq2-modified nanocrystalline Ti02 electrode.
A New Efficient Synthesis of Bisphenol A Diether Bis-imidazoles and Bis-benzimidazoles
Cheng He ZHOU , Jun WEI , Zhong Jun LI , Ru Gang XIE , Meng Shen CAI
1998, 9(10): 917-918
[Abstract](199) [FullText HTML] [PDF 81KB](2)
Abstract:
A new efficient synthesis of bisphenol A diether bis-imidazoles and bis-benzimidazoles by bromoalkylation and imidazolylation or benzimidazolylation two-step reactions from commercial bisphenol A, imidazole, 2-methylimidazole and benzimidazole is reported.
Synthesis and Steric Structure of β-Lactam Derivatives of 2,4-Diaryl-2,3-dihydro-1,5-benzothiazepines
Qi Yi XING , Yuan LI , Cat Yun DU , Qiu Qing YANG , Na SUN , Sheng JIN
1998, 9(10): 919-922
[Abstract](187) [FullText HTML] [PDF 98KB](0)
Abstract:
This paper reports the primary results of the study on p-lactam derivatives of 2,4-diaryl-2,3-dihydro-l,5-benzothiazepines. Five title compounds have been synthesized, and their configuration and conformation were determined by X-ray crystailographic analysis.
A Novel Type of Lower-Rim-Connected Double-Calix [6]arenes Composed of A 1,2,4-Triply Bridged and A Normal Calix [6]arene
Jian Sen LI , Yuan Yin CHEN , Zhen Lin ZHONG , Xue Ran LU
1998, 9(10): 923-926
[Abstract](303) [FullText HTML] [PDF 164KB](0)
Abstract:
The synthesis and characterization of the first example of lower-rim-connected double-calix [6]arene are reported, in which a 1,2,4-triply bridged calix [6]arene subunit is connected to a calix [6]arene subunit via a polyether chain.
Partial Synthesis of Macrolide Alkaloid Euonine
Yuan Chao LI , Shan Hao JIANG , Xiao Yi WANG
1998, 9(10): 927-928
[Abstract](184) [FullText HTML] [PDF 70KB](0)
Abstract:
The macrolide alkaloid euonine 1 with pharmacologic activity was prepared from the alkaloid wilforgine 2. Their structures were confirmed by IR, NMR, MS and optical rotation.
Stereoselective Total Synthesis of Chrysanthemol
Li Yuan MOU , Li Ya ZHU , Xiao Tian LIANG
1998, 9(10): 929-930
[Abstract](280) [FullText HTML] [PDF 87KB](0)
Abstract:
Chrysanthemol, an active antiinflammatory sesquiterpene from Chrysanthemum indicum L., was synthesized in ten steps from R-(+)-carvone with an overall yield of 2.4%. The analytic data of the synthetic target compound was identical with that of natural chrysanthemol.
Synthesis and Characterization of Both Enantiomers of a Chiral C60 Derivative Bearing the 1, 1'-Binaphthyl Group
Chuan Feng CHEN , Gai Jiao JI , Ji Sheng LI , Dao Ben ZHU
1998, 9(10): 931-934
[Abstract](193) [FullText HTML] [PDF 127KB](1)
Abstract:
Both enantiomers R-l and S-l of a chiral C60 derivative were synthesized by the reactions of C60 with 1, l'-bi-2-naphthol bis(azidoacetates) and characterized by FD-MS, FT-IR, 1H NMR, 13C NMR, UV-VIS, CD spectra.
Two New Polyoxygenated Cyclohexenes from Uvaria calamistrata
Guang Xiong ZHOU , Ruo Yun CHEN , De Quan YU
1998, 9(10): 935-938
[Abstract](290) [FullText HTML] [PDF 160KB](0)
Abstract:
Two new polyoxygenated cyclohexenes, named uvacaloIA (l), and B (2) were isolated from the rhizomes of Uvaria calamistrata. On the basis of spectral analysis and chemical derivatization, including preparation of Mosher esters, the structure of 1 to 2 were established.
A New Sesquiterpene from Michelia yunnanensis
Xin HONG , Bin Gut WANG , Jun ZHOU , Xiao Jiang HAO
1998, 9(10): 939-940
[Abstract](188) [FullText HTML] [PDF 76KB](0)
Abstract:
A new sesquiterpene, 12,13-di-acetoxyl-1,4,6,11-eudesmanetetrol 1, was isolated from Michelia yunnanensis. The structure was elucidated on the basis of spectral data.
Analysis of Chlorogenic Acid in Herbal Medicines by Capillary Electrophoresis
Hong LONG , Jin Jie YANG , Hu Wei LIU , Tian Song WANG , Ai Jin HUANG , Yi Liang SUN
1998, 9(10): 941-944
[Abstract](176) [FullText HTML] [PDF 152KB](0)
Abstract:
A simple, rapid and accurate capillary zone electrophoresis method was developed for the determination of chlorogenic acid as a marker in traditional Chinese medicines. The buffer solution comprised of 10 mmol/L sodium phosphate and 20 mmol/L boric acid containing 5% ethanol with the pH value adjusted to 7.00. The contents of chlorogenic acid in Flos Lonicerae and Flos Lonicerae containing herbal preparations were determined within 15 min.
Effect of Cl- ion on Anodic Iron Dissolution in H2S-Containing Sulfuric Acid Solutions
Li Jing YAN , Lin NIU , Hai Chao LIN , Wei Tao WU , Shang Zhang LIU
1998, 9(10): 945-948
[Abstract](199) [FullText HTML] [PDF 147KB](1)
Abstract:
The effect of Cl- ion on the anodic iron dissolution in H2SO4 solutions containing H2S has been studied by using electrochemical polarization curve measurements. The competitive adsorption for Cl- and HS- ions at an anodic potential has been calculated using the CNDO/2 method. The results show that a certain concentration of the Cl- ion can be adsorbed steadily and inhibit the anodic reaction of iron catalyzed by HS-. However, when the Cl- ion reaches the saturation adsorption, it begins to promote the anodic reaction of iron due to the increased negative charge of iron atoms.
Adsorption Chronopotentiometric Determination of Aluminum in Drinking Waters by Cupferron
Shu Ping BI , Yi GONG , Lei YE , Jing LI
1998, 9(10): 949-951
[Abstract](183) [FullText HTML] [PDF 135KB](0)
Abstract:
A novel and very sensitive electroanalytical method, based on the adsorption chronopotentiometry in the presence of cupferron,was developed for the determination of trace levels of aluminum. The working linear range is 2×lO-9-9×lO-7 mol/L and the detection limit is 1×1O-9 mol/L. It has been successfully applied to the determination of A1 in various drinking-water samples.
31P NMR Spectral Evidence for the Formation of Amino Acid Highcoordinated Phosphorus Intermediates
He Gui GONG , Hua FU , Zhao Long LI , Yu Fen ZHAO
1998, 9(10): 953-955
[Abstract](198) [FullText HTML] [PDF 113KB](0)
Abstract:
The active intermediates of hexacoordinated 4-nitrotrispirophosphoric amino acid (P(6)-AA), which were formed by the reaction of 4-nitro-0,0-phenylene phosphochloridate (NO-PPC) with silanizing serine, threonine and cysteine, were observed by 31P NMR spectra. The reaction mechanism of these processes was discussed. In addition, some interesting results were observed by mixing 4-nitro-2,2,2-tricloro-l,3, 2-benzodioxaphosph(v)ole (NTB) with silanizing serine and histidine.
Metabolites of Icariin in the Gastrointestine of Rats Following Oral Administration
Feng QIU , Ming Ze GU , Qing Song TAN , Ying Jie CHEN , Yoshihiro KANO , Xin Sheng YAO
1998, 9(10): 957-959
[Abstract](277) [FullText HTML] [PDF 128KB](0)
Abstract:
Further investigation of the metabolites of orally administered icariin in rats was made. Two minor metabolites, icariside I and icariside Ⅱ, were identified in gastric content, and two metabolites, icariside Ⅱ and icaritin, in intestinal content. The major metabolic route of icariin was proposed.
Discrimination of Structural Isomers of Aromatic Compounds with EI Mass Spectra and Their Ionization Efficiency Curves of Dehydrogenated Fragment Ions
Zeper ABLIZ , Li Jun LI , Teruo KAN , Toyotoshi UEDA
1998, 9(10): 961-964
[Abstract](192) [FullText HTML] [PDF 140KB](0)
Abstract:
The mechanism of ionization and fragmentation for terphenyl (diphenylbenzene) with three structural ring isomers (ortho-, meta-and para-), and stilbene (1,2-diphenylethylene) with two geometrical isomers (trans-and cis-) by EI mass spectrometry and ionization efficiency curves are investigation.
Recovery of Uniaxially Stretched Amorphous Poly (ethylene terephthalate) Film
Nan Jian SUN , De Yan SHEN
1998, 9(10): 965-966
[Abstract](200) [FullText HTML] [PDF 78KB](0)
Abstract:
Recovery behavior of uniaxially stretched amorphous poly (ethylene terephthalate) (a-PET) film near glass transition temperature (Tg) was studied. A strain recovery curve showed that the recovery was made up of two components each with different relaxation time.
Highly Ordered LB Films of Amphiphilic Complexes With 8-Hydroxyquinoline
Jian Ming OUYANG , Wei Han LING , Chuan LI
1998, 9(10): 967-970
[Abstract](260) [FullText HTML] [PDF 121KB](0)
Abstract:
Amphiphilic complexes of N-octadecyl-8-hydroxy-2-quinoline carboxamide, M (O-Q)2, form stable monolayer on pure water subphase and can be easily fabricated as highly ordered and uniform LB films, which were characterized by absorption spectra and low-angle X-ray diffraction measurements.
Polyimide structure-Property Relationships I. Polyimide Properties vs Dianhydride Configuration
Yue Jin TONG , Yan Xiang CHENG , Meng Xian DING , Yan XING , Yong Hua LIN
1998, 9(10): 971-972
[Abstract](254) [FullText HTML] [PDF 96KB](0)
Abstract:
X-ray crystal structures of 2,2',3,3'-and 3,3',4,4-biphenyltetracarboxylic dianhydride (2,2',3,3'-and 3,3',4,4'-BPDA) were determined. The dianhydride isomers have different symmetry caused by difference in two anhydride group positions and the dihedral angles between the two phenyl rings are 62.9°for 2,2',3,3',-BPDA and 0°for 3,3',4,4'-BPDA respectively. The polyimides from 2,2',3,3'-BPDA exhibit enhanced solubility, higher thermal stability, and higher glass transition temperature (Tg) compared with those from 3,3',4,4'-BPDA.
Synthesis and Characterization of Manganese Carbonyl Compounds with PNP
Shi Hua WU , Qin Xing XIE , Xiu Lin YANG , Wei Ping HUANG , Feng LU , Jin Pei CHENG
1998, 9(10): 973-975
[Abstract](186) [FullText HTML] [PDF 105KB](0)
Abstract:
Two new carbonyl manganese compounds were obtained by reactions of 2.6-di (bi-phenylphosphine) pyridine (PNP) with CpMn(CO)3.The structures of the compounds were confirmed by elemental analysis, IR,1H NMR and 31P NMR. The results showed that the mixed-donor ligand (PNP) was coordinated to manganese only through the phosphorus atom.
Synthesis and Crystsl Structure of a Novel Mercapto-organotin Complex:[Et3NH] [Ph2SnCl(μ2-SCH2COO-)]
Xue Qing SONG , Qing Lan XIE , Xiao Niu FANG
1998, 9(10): 977-978
[Abstract](281) [FullText HTML] [PDF 80KB](1)
Abstract:
A novel complex [Et3NH] [Ph2SnCl(μ2-SCH2COO-)] has been unexpectedly obtained by the reaction of Ph3SnCl and HSCH2COOH in 2:1 molar ratio in the presence of organic base Et3N. Possible dephenylation mechanism was illustrated. The X-ray diffraction study has shown that the title complex consists of cation moiety [Et3NH] and anion moiety [Ph2SnCl(μ2-SCH2COO-)]with tin(IV) in a trigonal bipyramidal coordination geometry.
Address:Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888
Powered By info@rhhz.net