1996 Volume 7 Issue 12

A Study on the Regioselectivity of the Cyclization Reaction of 5-Amino-1, 2, 4-triazole with Asym-l,3-dicarbonyl Compound
Rong Jian LU , Gao Feng ZHAO , Hua Zheng YANG
1996, 7(12): 1067-1068
[Abstract](156) [FullText HTML] [PDF 110KB](0)
Abstract:
This paper reports the primary results of the study on the regioselectivity of the cyclization reaction of 5-amino-1,2,4-triazole and its analogues with asym-1,3-dicarbonyl compounds.The mechanistic explanation for the regioselectivity is presented.
Regioselechve Reaction of α-(Alkoxydimethylsilyl)allyl Carbanions with Alkyl Halides and Aldehydes
Li LIU , Lab Hai LI , Dong WANG
1996, 7(12): 1069-1072
[Abstract](172) [FullText HTML] [PDF 199KB](0)
Abstract:
The reactions of α-(alkoxysilyl)allyl anions 4 with electrophiles were studied.α-Alkylation with alkyl halides was favoured,whereas γ-selection was achieved in the reaction with aldehydes.
Studies on the Reaction of 3-Substituted-4-Hydroxy-2H-1, 2-Benzothiazine 1, 1-Dioxides with Phenyl Isocyanate
Guo Feng ZHAO , Rong Jian LU , Hua Zheng YANG
1996, 7(12): 1073-1076
[Abstract](155) [FullText HTML] [PDF 151KB](0)
Abstract:
The reaction between 3-substituted-4-hydroxy-2H-1,2-benzothiazine 1,1-dioxides and phenyl isocyanate in the presence of different equivalents of strong base NaH has been studied.The structures of new derivatives were characterized by 1H NMR.IR.elementary analysis and FeCl3 test.
Homologation of Taxol Side Chain via Arndt-Eistert Reaction Involving the Wolff Rearrangement
Guang Yan HUANG , Yu GUO , Xiao Tian LIANG
1996, 7(12): 1077-1078
[Abstract](167) [FullText HTML] [PDF 98KB](0)
Abstract:
Homologation of protected taxol side chain Homologation of protected taxol side chain 8 from 4 was accomplished stereospecifically through the key intermediate diazo ketone 5 which was actually isolated.The structures of 5 and 7 were identified by spectrometric methods,mainly 1H-NMR,IR,13C-NMR and DEPT techniques.
A Facile Synthesis of (-)-5 αH,7β,10α-Eudesmane-3,11-diene
Ning ZOU , Dong Liang CHENG , Xin Fu PAN , Yao Zu CHEN
1996, 7(12): 1081-1082
[Abstract](160) [FullText HTML] [PDF 72KB](0)
Abstract:
The convenient synthesis of (-)-5αH,7β,10α-eudesmane-3,11-diene 1 has been achieved in four steps starting from R-(-)-carvone.The key step is the reductive deoxygenation of α,β-unsaturated tosylhydrazone together with the migration of the double bond.
Stereoselective Synthesis of (Z)-β-Aryltellurocinnamic Esters
Chang Qiu ZHAO , Xian HUANG
1996, 7(12): 1083-1084
[Abstract](165) [FullText HTML] [PDF 78KB](0)
Abstract:
Aryl telluroesters were prepared from the reaction of tellurium and Grignard reagents then acylation with acyl chlorides.Addition of telluroesters to arylpropiolates produced (2Z)-β-aryltelluro-α,β-unsaturated esters with high stereoselectivity.
A New and Effective Synthesis of Terminal Alkylselenylacetylenes
De Yu YANG , Xian HUANG , Ping LI
1996, 7(12): 1085-1086
[Abstract](161) [FullText HTML] [PDF 93KB](0)
Abstract:
The terminal alkylselenylacetylenes (RSe-C≡C-H) 3a-h were prepared by the reaction of ethynylmagnesium bromide at -20℃ in THF with alkylselenyl bromides derived from dialkyl diselenides and bromide.
The Synthesis and Biological Activity of N-Arylamino Carbonyl Methylene 1,2-Benzothiazine 1,1-Dioxides
Guo Feng ZHAO , Hua Zheng YANG
1996, 7(12): 1087-1088
[Abstract](165) [FullText HTML] [PDF 82KB](0)
Abstract:
In this paper four new 1,2-benzothiazine 1,1-dioxide derivatives 4 were synthesized by the reaction of 4-ethylenedioxy-2H-1,2-benzothiazine 1,1-dioxide 2 with 2-chloroacetamides 3 under the action of base.The biological tests indicated that these four compounds have good herbicidal activity.
Synthesis of 3-(R)-(Adenin-9'-yl)-4-(R)-Hydroxy-5-(R)-Hydroxymethyltetrahydrofuran
Hu Yi ZHANG , Xue Jun WU , Hong Wu YU , Ling Tai MA , Li He ZHANG
1996, 7(12): 1089-1090
[Abstract](160) [FullText HTML] [PDF 85KB](0)
Abstract:
3-(R)-3-(adenin-9'-yl)-4-(R)-hydroxy-5-(R)-hydroxymethyltetrahydrofuran was synthesized by the regeoselective substitution of 3,4-epoxy-(trans)-5-(R)-dimethoxymethyltetrahydrofuran which was obtained by 4 steps from L-xylose.
A New Mathod for Conversion of Nitriles to Primary Alcohols
Guang Dian HAN , Song Kee CHUNG
1996, 7(12): 1089-1080
[Abstract](164) [FullText HTML] [PDF 67KB](0)
Abstract:
A new method for direct conversion of nitrites to primary alcohols using ZnCoCI2 reagent in AcOH/EtOH system is reported.
The Site-Specific Hydrolysis of l-β-Hydroxybaccatin Ⅰ by Aspergillus Niger
Jun Zeng ZHANG , Li He ZHANG , Di An SUN , Jian Qiao GU , Qi Cheng FANG
1996, 7(12): 1091-1092
[Abstract](172) [FullText HTML] [PDF 91KB](0)
Abstract:
The site-specific microbiological hydrolysis of a natural taxoid,1β-hydroxybaccatin I,with the culture of Aspergillus niger,is described.
Eudesmanes and Eudesmanoic Glucosides from Laggera pterodonta
Yu ZHAO , Jian Min Yue , Jing Kai DING , Zhong Wen Lin , Han Dong SUN
1996, 7(12): 1093-1094
[Abstract](156) [FullText HTML] [PDF 104KB](0)
Abstract:
-Phytochemical re-investigation of the anti-leukemia plant Laggera pterodonta afford four new eudemsanes (1-4) and six new eudesmanoic glucosides (5-10).Their structures were elucidated by high field 1D and 2D NMR techniques and chemical methods.
New Pyrones from Hypericum Japonicum
Qing Li WU , Yong Hong LIAO , Sheng Ping WANG , Li Wei WANG , Yu Xiu FENG , Jun Shan YANG , Pei Gen XIAO , Shao Liang HONG
1996, 7(12): 1095-1096
[Abstract](156) [FullText HTML] [PDF 92KB](0)
Abstract:
From the aerial part of Hypericum Japonicum Thunb.ex Murray,two new pyrones,japonicumone-A and-B,were isolated and their structures were determined on basis of spectroscopic evidence.
Subvellerolactone C, a New Lactarane Sesquiterpene from Lactarius Subvellereus
Jing ZHANG , Xiao Zhao FENG
1996, 7(12): 1097-1099
[Abstract](164) [FullText HTML] [PDF 129KB](0)
Abstract:
Subvellerolactone C(I),a new 3,8-oxa-13-hydroxy-lactar-6-en-5-oic acid γ-lactone was isolated from the fruit bodies of Lactarius Subvellereus (Russulaceae),and its structure was elucidated by means of spectroscopic methods(UV,IR,HRMS,1H-NMR,13C-NMR,13C-1HCORR.,1H-1HCOSY,HMBC,NOEDIFF.).
Two New Sesquiterpenes from Ligularia Intermedia
Hong Ming CHEN , Meng Shen CAI , Zhong Jian JIA
1996, 7(12): 1100-1102
[Abstract](153) [FullText HTML] [PDF 98KB](0)
Abstract:
Two new sesquiterpenes were isolated from the rhizomes of Ligularia Intermedia.Their structures were determined as eremophil-7(8)-en-12,8(4β,6α)-diolide(1) and eremophil-7(8)-en-12,8(4β,6β)-diolide(2) by spectroscopic methods
HPCE Enantiomeric Separation of Nafronyl Oxalate
Hut JIN , Fang LI , Jun Ling GU , Ruo Nong FU
1996, 7(12): 1103-1104
[Abstract](160) [FullText HTML] [PDF 63KB](0)
Abstract:
The addition of methanol to the buffer enhanced 2,6-di-O-carboxymethyl-β-CD's enantioselectivity to nafronyl oxalate,of which four enantiomers were separated in CZE successfully.
The Molecular Shape Effect in the Separation of Ionic Isomers by Capillary Zone Electrophoresis
Shi Ze QI , Xiao Hong FANG , Ai Jin HUANG , Yi Liang SUN
1996, 7(12): 1105-1108
[Abstract](151) [FullText HTML] [PDF 191KB](0)
Abstract:
The present understanding of electrophoretic mobility cannot satisfactorily be used to explain the separation capability of capillary zone electrophoresis for isomeric anions.A molecular shape effect concept was proposed to describe the separation mechanism for isomeric anoins with o-,m-,p-hydroxybenzoates and two food colorants,amaranth and ponceau 4R as examples.
Preparation and Evaluation of Polyethylene Glycol Acrylate Coated Capillary Zone Elcctrophoresis Column
Xiao Hong FANG , Ai Jin HUANG , Yi Liang SUN
1996, 7(12): 1109-1112
[Abstract](145) [FullText HTML] [PDF 189KB](0)
Abstract:
Polyethylene glycol acrylate was covalently bound onto the capillary surface and crosslinked by azobisisobutyronitrile(AIBN).The coating is stable over pH 2-9,has a good coating reproducibility and can be used for the separation of proteins and polypeptides.
High-Performance Liquid Chromatographic Determination Of N-Nitrosoamines by Pre-Column Fluorescence Derivatization with 9-Phenanthrene Chloride
Jin Mao YOU , Bin ZRAO , Qing Cun ZHU
1996, 7(12): 1113-1116
[Abstract](165) [FullText HTML] [PDF 185KB](0)
Abstract:
A sensitive high-performance chromatographic method for the detection of N-nitrosoamines with pre-column fluorescence derivatization has been developed.Eight representative N-nitrosoamines,which were separated on a reversed-phase C18column with methanol-water-triethylamine as eluent,were used as model compounds to optimize the derivatization and the chromatographic conditions.The relative standard deviations(n=7) at an analytical concentration of 4×10-6 mol/L are less than 5%.The detection limits (signal-to-noise ratio=3) for the N-nitrosoamines compounds are in the range of 0.02~0.14 nmol per injection volume(10 μl).
Studies on the Absorption Spectra of Aqueous L-Tyrosine and Its Application
Jia Zhen YANG , Zi Fu ZHANG , Jun LIU
1996, 7(12): 1117-1120
[Abstract](161) [FullText HTML] [PDF 163KB](0)
Abstract:
The absorption spectra of agueous L-tyrosine at various total ionic strengths were measured by UV-240 spectrophotometer at 298.2±0.2K and the standard third dissociation constant of L-tyrosine was determined from the spectra by linear extrapolation and polynomial approximation.
Study on the Photofading of Near-Infrared Absorbing Indolenine Cyanines Dyes
Jun LI , Ping CHEN , Xiu Jie HU , De Shut ZHENG , Tsuneki Okasaki , Masaaki Hayami
1996, 7(12): 1121-1124
[Abstract](158) [FullText HTML] [PDF 141KB](0)
Abstract:
The spectroscopic properties and photostability of three near-infrared absorbing indolenine cyanine dyes have been studied.It was found that photofading of cyanine dyes was mainly caused by photooxidation,and their photostability increased significantly when the cyclic unity was introduced into the polymethine chain.
Measurement and Calculation of Quenching Rate Constants for PCl(b)
Sheng Li ZOU , Chuan Pu LIU , Jing Zhong GUO , Yue Shu GU , Yan Nan Chu , De Zhao CAO
1996, 7(12): 1125-1126
[Abstract](164) [FullText HTML] [PDF 95KB](0)
Abstract:
Using the Ar(3P0.2)+PCl3 reaction as a source of PCl(b1Σ+),We have measured the quenching rate constants of PCl(b) for 23 reagents.The E-V model is used to calculate the rate constants.The comparison between the experimental and calculated results is given.
Ruthenium Coordination Compounds with Polypyridines Ⅶ. Non-intercalative Binding of Ru(Ⅱ) Complexes with Calf Thymus DNA
Guang YANOG , Jian Zhong WU , Lei WANG , Tian Xian ZENG , Liang Nian JI , Xuan TIAN
1996, 7(12): 1127-1130
[Abstract](156) [FullText HTML] [PDF 184KB](0)
Abstract:
Two new ruthenium polypyridine complexes,L2RuL'2+, where L=2,2'-bipyridine (bpy) and 2,9-dimethyl-1,10-phenanthroline (dmp);L' is Schiff base prepared from condensation of 4,5-diazafluoren-9-one (AFO) and aniline,have been prepared and characterized by elemental analyses,electronic absorption,IR spectra.The binding of the complexes to calf thymus DNA has been investigated by absorption,emission spectra and circular dichroism spectroscopy.Experimental results show these two complexes bind to DNA by electrostatic mode and non-intercalative binding mode.
The Responsivity of the Bacteriorhodopsin Langmuir-Blodgett Film Intermittent Light
Guang Yu WANG , Jian Hua YANG , Zhi Guang ZHANG , Shu Huang LIN , Tao LU , Bao Fang LI , Long JIANG
1996, 7(12): 1131-1134
[Abstract](166) [FullText HTML] [PDF 195KB](0)
Abstract:
Self Assembled Monolayer Films of C60 on O,O'-Bis(2-aminoethyl)dithiophos Modified Copper
Xiao Yu CHEN , Yu HAN , Ling QI , Zheng XU , Lan Sun ZHENG
1996, 7(12): 1135-1138
[Abstract](164) [FullText HTML] [PDF 146KB](0)
Abstract:
On the surface of O,O'-bis(2-aminoethyl) dithiophosphate modified copper C60forms self-assembled monolayer films (SAMs) through the chemical bond.The film was characterized by contact angle,X-ray photoelectron spectroscopy,electrochemistry,TOF Mass Spectropy
Synthesis of Terminal Amino Substituted Cyclopentadienyl Titanium Complexes
Yan Long QIAN , Rong Wei GUO , Ji Ling HUANG , Klaus JONAS
1996, 7(12): 1139-1142
[Abstract](153) [FullText HTML] [PDF 144KB](0)
Abstract:
the synthesis of twelve new tenninal amino substituted titanocene dichlorides is reported.
A New Approach for Stabilizing Organouranium Dichloride: Synthesis and X-ray Structure of (MeOCH2CH2C5H4)2UCl2
Dao Li DENG , Xiao Fan ZHANG , Chang Tao QIAN , Jie SUN , Pei Ju ZHENG , Jian CHEN
1996, 7(12): 1143-1144
[Abstract](145) [FullText HTML] [PDF 104KB](0)
Abstract:
Cp'2UCI2(Cp'=MeOCH2CH2C5H4) complex 1 has been synthesized by the reaction of UCI4 with Cp'Na in tetrahydrofuran.A single-crystal X-ray study shows that the uranium compound is a mononuclear complex with uranium in a pseudo-hexahedral co-ordination geometry if the cyclopentadienyl ring is regarded as occupying a single polyhedral vertex.
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