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1997 Volume 8 Issue 12
1997, 8(12): 1013-1014
Abstract:
Benzaldehyde has been trimethylsilylcyanated with a catalyst prepared in situ from titanium tetraisopropoxide and chiral Schiff bases.Cyanohydrin is obtained in moderate e.e.values.
Benzaldehyde has been trimethylsilylcyanated with a catalyst prepared in situ from titanium tetraisopropoxide and chiral Schiff bases.Cyanohydrin is obtained in moderate e.e.values.
1997, 8(12): 1015-1016
Abstract:
A number of chiral quaternary ammonium salts were synthesized from (1R,2S)-(-)-1,2-diphenyl-2-aminoethanol and applied to the enantioselective alkylation.
A number of chiral quaternary ammonium salts were synthesized from (1R,2S)-(-)-1,2-diphenyl-2-aminoethanol and applied to the enantioselective alkylation.
1997, 8(12): 1017-1018
Abstract:
N-Trimethylsilylvaline trimethylsilyl ester Ⅱa,N-triethylsilylvaline triethylsilyl ester Ⅱb and N-tert-butyldimethylsilylvaline tert-butyldimethylester Ⅱc showed evidently different reactivities with O,O'-phenylenephosphorylchloride.The formation speed of the final spiro-bicyclic pentacoordinated phosphorus compounds Ⅳ depends on the intramolecular transfer ability of the silyl oiety crucially.
N-Trimethylsilylvaline trimethylsilyl ester Ⅱa,N-triethylsilylvaline triethylsilyl ester Ⅱb and N-tert-butyldimethylsilylvaline tert-butyldimethylester Ⅱc showed evidently different reactivities with O,O'-phenylenephosphorylchloride.The formation speed of the final spiro-bicyclic pentacoordinated phosphorus compounds Ⅳ depends on the intramolecular transfer ability of the silyl oiety crucially.
1997, 8(12): 1019-1020
Abstract:
Asymmetric 1,3-dipolar cycloaddition of the chiral nitronic esters with acrylate giving the enantiomerically pure novel chiral bisheterocyclic compounds is described.
Asymmetric 1,3-dipolar cycloaddition of the chiral nitronic esters with acrylate giving the enantiomerically pure novel chiral bisheterocyclic compounds is described.
1997, 8(12): 1021-1024
Abstract:
Fourteen new 2-acylhydrazino-5-(2,4-dichlorophenyl)-1,3,4-oxadiazoles were prepared by nucleophilic displacement of acylhydrazine at the 2-position of 2-methylsulfonyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole.Fourteen new 3-substituted-6-(2,4-dichlorophenyl)-s-triazolo[3,4-b]-1,3,4-oxadiazoles were obtained by treating 2-acylhydrazino-5-(2,4-dichlorophenyl)-1,3,4-oxadiazoles with K2CO3 solution.All the new compounds showed significant antibacterial activity.
Fourteen new 2-acylhydrazino-5-(2,4-dichlorophenyl)-1,3,4-oxadiazoles were prepared by nucleophilic displacement of acylhydrazine at the 2-position of 2-methylsulfonyl-5-(2,4-dichlorophenyl)-1,3,4-oxadiazole.Fourteen new 3-substituted-6-(2,4-dichlorophenyl)-s-triazolo[3,4-b]-1,3,4-oxadiazoles were obtained by treating 2-acylhydrazino-5-(2,4-dichlorophenyl)-1,3,4-oxadiazoles with K2CO3 solution.All the new compounds showed significant antibacterial activity.
1997, 8(12): 1025-1028
Abstract:
Four kinds of new macrocycles containing amino acids and aryl-heterocyclic units were synthesized by the condensation of di-esters containing Ts-amino acids units with di-halogenated compounds at room temperature.The macrocycles were characterized by elemental analysis,IR,MS(FAB) and 1H NMR.
Four kinds of new macrocycles containing amino acids and aryl-heterocyclic units were synthesized by the condensation of di-esters containing Ts-amino acids units with di-halogenated compounds at room temperature.The macrocycles were characterized by elemental analysis,IR,MS(FAB) and 1H NMR.
1997, 8(12): 1029-1030
Abstract:
Benzoylated phenyl α-and β-2-thio-D-fructofuranosides were synthesized and firstly used as donors in coupling with sucrose acceptor.α-Fructofuranoside was stereospecifically synthesized by employing NIS (N-iodosuccinimide)/AgOTf as catalysts.The structure of all products was confirmed by 13C-NMR or 1H-NMR spectrum.
Benzoylated phenyl α-and β-2-thio-D-fructofuranosides were synthesized and firstly used as donors in coupling with sucrose acceptor.α-Fructofuranoside was stereospecifically synthesized by employing NIS (N-iodosuccinimide)/AgOTf as catalysts.The structure of all products was confirmed by 13C-NMR or 1H-NMR spectrum.
1997, 8(12): 1031-1032
Abstract:
4,5-diphenyl,4,5-bis(4-methylphenyl),4,5-bis(4-methoxyphenyl)-2-(2,5-dimethylthiophen-3-yl) imidazoles were synthesized.Oxidation of the obtained imidazoles with potassium ferricyanide in water-alcohol solution of alkali gave the corresponding dimers.The structures of imidazoles were characterized by IR,1H NMR,mass spectroscopy and elemental analysis.The structures of dimers were characterized by IR,elemental analysis and chromatography.
4,5-diphenyl,4,5-bis(4-methylphenyl),4,5-bis(4-methoxyphenyl)-2-(2,5-dimethylthiophen-3-yl) imidazoles were synthesized.Oxidation of the obtained imidazoles with potassium ferricyanide in water-alcohol solution of alkali gave the corresponding dimers.The structures of imidazoles were characterized by IR,1H NMR,mass spectroscopy and elemental analysis.The structures of dimers were characterized by IR,elemental analysis and chromatography.
1997, 8(12): 1033-1036
Abstract:
A method for selective reaction of 1-aryl-propane-1-ones with 1,2-dihydroxy group of D-mannitol in the presence of ZnCl2-BF3.Et2O to 1,2-O-(1-aryl-1-propylidene)-D-mannitol (1-4) is described.The compounds were first reported and determined by IR,MS,1H-/13C-NMR spectra,among them the structure of 1 was further defined by X-ray diffraction.
A method for selective reaction of 1-aryl-propane-1-ones with 1,2-dihydroxy group of D-mannitol in the presence of ZnCl2-BF3.Et2O to 1,2-O-(1-aryl-1-propylidene)-D-mannitol (1-4) is described.The compounds were first reported and determined by IR,MS,1H-/13C-NMR spectra,among them the structure of 1 was further defined by X-ray diffraction.
1997, 8(12): 1037-1040
Abstract:
Total synthesis of gnetifolin A was accomplished via intramolecular Wittig reaction.The synthesis started from 2-methoxy-3-methylhydroquinone and methyl 4-O-methylgallate through eight steps.
Total synthesis of gnetifolin A was accomplished via intramolecular Wittig reaction.The synthesis started from 2-methoxy-3-methylhydroquinone and methyl 4-O-methylgallate through eight steps.
1997, 8(12): 1041-1042
Abstract:
The synthesis of 9β-acetoxy-3(4),11(13)-dien-5αH,7αH-12-eudesmanoic acid methyl ester (2) was achieved from oxycarvone.The key step is the p-toluenesulfonhydrazide assisted reductive rearrangement reaction.
The synthesis of 9β-acetoxy-3(4),11(13)-dien-5αH,7αH-12-eudesmanoic acid methyl ester (2) was achieved from oxycarvone.The key step is the p-toluenesulfonhydrazide assisted reductive rearrangement reaction.
1997, 8(12): 1043-1044
Abstract:
Tricyclic compound 6 was synthesized from compound 1 through six steps,thus problem of the stereochemistry of C2a-H being solved.The stereochemistry for introducing hydroxy groups at C3β and C4α positions in compound 1 was also described.
Tricyclic compound 6 was synthesized from compound 1 through six steps,thus problem of the stereochemistry of C2a-H being solved.The stereochemistry for introducing hydroxy groups at C3β and C4α positions in compound 1 was also described.
1997, 8(12): 1045-1046
Abstract:
Radical copolymerization of N-phenylmaleimide with cyclohexene was carried out with 2,2-azobisisobutyronitrile in various solvents at 60℃.The copolymer was characterized by IR and 1H-NMR.
Radical copolymerization of N-phenylmaleimide with cyclohexene was carried out with 2,2-azobisisobutyronitrile in various solvents at 60℃.The copolymer was characterized by IR and 1H-NMR.
1997, 8(12): 1047-1050
Abstract:
A series of novel phosphonoacetic acid derivatives,N-(ethoxycarbonylmethyl-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates,were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides or amino phosphonates in the presence of a base.The preliminary bioassay shows that some compounds show significant anti-viral activity against tobacco mosaic virus (TMV).
A series of novel phosphonoacetic acid derivatives,N-(ethoxycarbonylmethyl-ethoxyphosphonyl)-α-amino acid esters and α-amino phosphonates,were synthesized via the reaction of the corresponding phosphonyl chloride with amino acid ester hydrochlorides or amino phosphonates in the presence of a base.The preliminary bioassay shows that some compounds show significant anti-viral activity against tobacco mosaic virus (TMV).
1997, 8(12): 1051-1054
Abstract:
The allylic nature of C-10 in sinenxan A (1) leads to facile SN1 and elimination reactions.
The allylic nature of C-10 in sinenxan A (1) leads to facile SN1 and elimination reactions.
1997, 8(12): 1055-1056
Abstract:
A new taxoid taxa-4(20),11-diene-2α,5α,10β,14β-tetraol-2α,14β-diacetate (sinenxan H) (1) was obtained by biotransformation of taxa-4(20),11-diene-2α,5α,10β,14β-tetraol-2α,5α,10β,14β-tetraacetate (2) with a fungus isolated from Taxus yunnanensis.Its structure was determined based on spectral data.
A new taxoid taxa-4(20),11-diene-2α,5α,10β,14β-tetraol-2α,14β-diacetate (sinenxan H) (1) was obtained by biotransformation of taxa-4(20),11-diene-2α,5α,10β,14β-tetraol-2α,5α,10β,14β-tetraacetate (2) with a fungus isolated from Taxus yunnanensis.Its structure was determined based on spectral data.
1997, 8(12): 1057-1058
Abstract:
A new taxoid with 5/7/6 taxane skeleton,named taxamedin A (1) was isolated from the needles of Taxus×media Hicksii.Its structure was elucidated by spectral analysis.
A new taxoid with 5/7/6 taxane skeleton,named taxamedin A (1) was isolated from the needles of Taxus×media Hicksii.Its structure was elucidated by spectral analysis.
1997, 8(12): 1059-1060
Abstract:
Artselenin,a new guaianolide isolated from Artemisia selengensis and its structure determination by spectral data are reported.
Artselenin,a new guaianolide isolated from Artemisia selengensis and its structure determination by spectral data are reported.
1997, 8(12): 1061-1062
Abstract:
Two new diterpenoids,lungshengenin B and C (1-2),were isolated from Isodon lungshengensis.The structures were determined as 1α-hydroxy-2β,3β,11β,15β-tetraacetoxy-ent-kaur-16-en-6-one;11α-hydroxy-2β,3β,6α-triacetoxy-ent-kaur-16-en-15-one by 1D and 2D NMR techniques (COSY,HETCOR,COLOC).
Two new diterpenoids,lungshengenin B and C (1-2),were isolated from Isodon lungshengensis.The structures were determined as 1α-hydroxy-2β,3β,11β,15β-tetraacetoxy-ent-kaur-16-en-6-one;11α-hydroxy-2β,3β,6α-triacetoxy-ent-kaur-16-en-15-one by 1D and 2D NMR techniques (COSY,HETCOR,COLOC).
1997, 8(12): 1063-1064
Abstract:
Proton NMR-spectra of Wang resin bound compounds were obtained using the magic angle spinning 1HNMR technique with standard equipment.It was possible to analyse the spectra to evaluate their utility in solid-phase chemistry.A typical example was presented,which could directly monitor solid-phase reactions.
Proton NMR-spectra of Wang resin bound compounds were obtained using the magic angle spinning 1HNMR technique with standard equipment.It was possible to analyse the spectra to evaluate their utility in solid-phase chemistry.A typical example was presented,which could directly monitor solid-phase reactions.
1997, 8(12): 1065-1068
Abstract:
The Caltrate Weikang capsules made by us is a high potency calcium preparation,in which vitamin D can promote the body's calcium absorption and the bones calcification.A sensitive HPLC method for the determination of VD2 and VD3 in Caltrate Weikang capsules was established and VD stability was also examined.
The Caltrate Weikang capsules made by us is a high potency calcium preparation,in which vitamin D can promote the body's calcium absorption and the bones calcification.A sensitive HPLC method for the determination of VD2 and VD3 in Caltrate Weikang capsules was established and VD stability was also examined.
1997, 8(12): 1069-1070
Abstract:
A new diazoamino reagent 1-(4-antipyrinyl)-3-(3-Chlorophenyl)-triazene(APCPT) was synthesized.The colour reaction of APCPT with Hg(Ⅱ) was studied.At pH=10.5~12.2,in the presence of Tween-80,APCPT reacts with Hg(Ⅱ) to form a red complex with high sensitivity.The molar ratio of Hg(Ⅱ) to APCPT is 1:2.The molar absorptivity is 1.87×105L·mol-1·cm-1.Beer's law is obeyed for Hg in the range of 0-16μg/25ml.
A new diazoamino reagent 1-(4-antipyrinyl)-3-(3-Chlorophenyl)-triazene(APCPT) was synthesized.The colour reaction of APCPT with Hg(Ⅱ) was studied.At pH=10.5~12.2,in the presence of Tween-80,APCPT reacts with Hg(Ⅱ) to form a red complex with high sensitivity.The molar ratio of Hg(Ⅱ) to APCPT is 1:2.The molar absorptivity is 1.87×105L·mol-1·cm-1.Beer's law is obeyed for Hg in the range of 0-16μg/25ml.
1997, 8(12): 1071-1072
Abstract:
The semiconductive characteristics of electron-transferring proteins in living cells E.coli was investigated by electrochemical impedance spectroscopy (EIS).We found that the electrochemical impedance of living cells as a function of temperature followed the Arrhenius equation for semiconductors.This result shows a strong evidence to prove the semiconductive behavior of proteins.
The semiconductive characteristics of electron-transferring proteins in living cells E.coli was investigated by electrochemical impedance spectroscopy (EIS).We found that the electrochemical impedance of living cells as a function of temperature followed the Arrhenius equation for semiconductors.This result shows a strong evidence to prove the semiconductive behavior of proteins.
1997, 8(12): 1073-1074
Abstract:
The interaction of La(Ⅲ) with adrenaline was studied using Ab initio method.The geometry of the complex of La (Ⅲ) with adrenaline was optimized,and the La(Ⅲ) bonding site in adrenaline was ascertained.
The interaction of La(Ⅲ) with adrenaline was studied using Ab initio method.The geometry of the complex of La (Ⅲ) with adrenaline was optimized,and the La(Ⅲ) bonding site in adrenaline was ascertained.
