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1994 Volume 5 Issue 7
1994, 5(7): 549-550
Abstract:
(4S)-1-Ethoxysilatrane-4-carboxylic acid and (4S)-1-ethoxy-3-methylsilatrane-4-carboxylic acid were synthesized from the reaction of triethoxysilane with L-N,N-bis(2-hydroxyethyl) serine or L-N,N-bis(2-hydroxyethyl) threonine in the presence of pyridine.
(4S)-1-Ethoxysilatrane-4-carboxylic acid and (4S)-1-ethoxy-3-methylsilatrane-4-carboxylic acid were synthesized from the reaction of triethoxysilane with L-N,N-bis(2-hydroxyethyl) serine or L-N,N-bis(2-hydroxyethyl) threonine in the presence of pyridine.
1994, 5(7): 551-552
Abstract:
A compound,triptonide showed an antifertility activity,has been semi-synthesized from triptolide in 97% yield with chromic acid in one step.
A compound,triptonide showed an antifertility activity,has been semi-synthesized from triptolide in 97% yield with chromic acid in one step.
1994, 5(7): 553-554
Abstract:
Eleven new isoflavonoid derivatives which contain 3',4'-methylenedioxy,3',4'-ethylenedioxy,and 3',4'-trimethylenedioxy groups were synthesized.The structures of new compounds were confirmed by elemental analysis and 1H-NMR data.
Eleven new isoflavonoid derivatives which contain 3',4'-methylenedioxy,3',4'-ethylenedioxy,and 3',4'-trimethylenedioxy groups were synthesized.The structures of new compounds were confirmed by elemental analysis and 1H-NMR data.
1994, 5(7): 555-556
Abstract:
1-O-Acetyl-2,3,4-tri-O-benzoyl-β-D-ribofuranose reacted with alcohols or phenols in the presence of trimethylsilyl trifluoromethanesulfonate(TMSOTf) and molecular sieve (4Å) to give good yields of 1-O-alkyl-2,3,4-tri-O-benzoyl-β-D-ribofuranose.
1-O-Acetyl-2,3,4-tri-O-benzoyl-β-D-ribofuranose reacted with alcohols or phenols in the presence of trimethylsilyl trifluoromethanesulfonate(TMSOTf) and molecular sieve (4Å) to give good yields of 1-O-alkyl-2,3,4-tri-O-benzoyl-β-D-ribofuranose.
1994, 5(7): 557-560
Abstract:
2,3-Dihydro-1H-1,5-benzodiazepines and 1-benzoyl-2,3-dihydro-1H-1,5-benzodiazepines react with,α-carbonylketenes,generated from 2-diazo-1,3-diphenyl-1,3-propandione or 2-diazo-1-phenyl-1,3-butandione by heating,to give 4a,5,6,12-tetrahydro-1H,7H-1,3-oxazino[3,2-d] [1,5]-benzodiazepine-1-ones,a new ring system.2,3-Dihydro-1H-1,5-benzodiazepines also afford adducts of H-N bond with α-carbonylkelenes,2-aryl-1-(2-benzoyl-phenylacetyl)-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepines.Addition of benzonitrile N-phenylimine,yielded in situ from the N-phenyl benzenecarbohydrazonic chloride,to 2,4-diaryl-2,3-dihydro-1,5-benzothiazepines and 1H-1,5-benzodiazepine gave 3a,5-diaryl-1,3-diphenyl-3a,4,5,11-tetrahydro-3H-1,2,4-triazolo[4,3-d] [1,5]benzothiazepine and 3H,6H-1,2,4-triazolo[4,3-d] [1,5]benzodiazepine,respectively.
2,3-Dihydro-1H-1,5-benzodiazepines and 1-benzoyl-2,3-dihydro-1H-1,5-benzodiazepines react with,α-carbonylketenes,generated from 2-diazo-1,3-diphenyl-1,3-propandione or 2-diazo-1-phenyl-1,3-butandione by heating,to give 4a,5,6,12-tetrahydro-1H,7H-1,3-oxazino[3,2-d] [1,5]-benzodiazepine-1-ones,a new ring system.2,3-Dihydro-1H-1,5-benzodiazepines also afford adducts of H-N bond with α-carbonylkelenes,2-aryl-1-(2-benzoyl-phenylacetyl)-4-phenyl-2,3-dihydro-1H-1,5-benzodiazepines.Addition of benzonitrile N-phenylimine,yielded in situ from the N-phenyl benzenecarbohydrazonic chloride,to 2,4-diaryl-2,3-dihydro-1,5-benzothiazepines and 1H-1,5-benzodiazepine gave 3a,5-diaryl-1,3-diphenyl-3a,4,5,11-tetrahydro-3H-1,2,4-triazolo[4,3-d] [1,5]benzothiazepine and 3H,6H-1,2,4-triazolo[4,3-d] [1,5]benzodiazepine,respectively.
1994, 5(7): 561-562
Abstract:
The photoinduced intramolecular arene-olefin meta-cycloaddition was used as a key step in the synthesis of crinipellin ring skeleton.The structures of the photo products were established by 1H,13C-NMR method.
The photoinduced intramolecular arene-olefin meta-cycloaddition was used as a key step in the synthesis of crinipellin ring skeleton.The structures of the photo products were established by 1H,13C-NMR method.
1994, 5(7): 563-564
Abstract:
An efficient synthesis of (5R)-7,7-dimethoxy-5-[1-(2-tert-butyldiphenylsiloxymethyl)vinyl]-2-heptanone,a key intermediate in the synthesis of antitumor cembrane type sinuiariol-D,sinularial-A and sinuiaric acid-A isolated from the soft coral Sinularin moyi was first described from (R)-limonene.
An efficient synthesis of (5R)-7,7-dimethoxy-5-[1-(2-tert-butyldiphenylsiloxymethyl)vinyl]-2-heptanone,a key intermediate in the synthesis of antitumor cembrane type sinuiariol-D,sinularial-A and sinuiaric acid-A isolated from the soft coral Sinularin moyi was first described from (R)-limonene.
1994, 5(7): 565-566
Abstract:
Cu2O-catalyzed cycloaddition of 1-isocyanoalkylphosphonate to electron-deficient olefins gave 3,4-dihydro-2H-pyrrole-2-phosphonates.
Cu2O-catalyzed cycloaddition of 1-isocyanoalkylphosphonate to electron-deficient olefins gave 3,4-dihydro-2H-pyrrole-2-phosphonates.
1994, 5(7): 567-568
Abstract:
The modified procedure of the catalytic asymmetric epoxidation of the α-furfurylamines (dl)-1a-d in the presence of molecular sieve and CaH2 provides the slow-reacting enantiomers (S)-1a-d and the fast-reacting enantiomers (2R.6S)-2a-d in high enantioselectivity and high chemical yield.
The modified procedure of the catalytic asymmetric epoxidation of the α-furfurylamines (dl)-1a-d in the presence of molecular sieve and CaH2 provides the slow-reacting enantiomers (S)-1a-d and the fast-reacting enantiomers (2R.6S)-2a-d in high enantioselectivity and high chemical yield.
1994, 5(7): 569-572
Abstract:
A new kind of inorganic polymer silica-supported polytitazane (Ti-N),and its platinum-manganese bimetallic complex (Ti-N-Pt-Mn)were prepared.The activity and selectivity to cyclohexanone in the hydrogenation of phenol over Ti-N-Pt-Mn can be affected by Pt/Mn molar ratio in the complex,reaction temperature and solvent etc.
A new kind of inorganic polymer silica-supported polytitazane (Ti-N),and its platinum-manganese bimetallic complex (Ti-N-Pt-Mn)were prepared.The activity and selectivity to cyclohexanone in the hydrogenation of phenol over Ti-N-Pt-Mn can be affected by Pt/Mn molar ratio in the complex,reaction temperature and solvent etc.
1994, 5(7): 573-576
Abstract:
Resting cells of Nocardia sp.were used to convert a series of unsaturated long-chain fatty acids to 10-hydroxy fatty acids.Structures of all metabolites were suggested by 1H nuclear magnetic resonance and by infrared and mass spectrum.The results showed that the hydroxylation stereospecificity happened at the cis-9 double bond with other position unaffected.
Resting cells of Nocardia sp.were used to convert a series of unsaturated long-chain fatty acids to 10-hydroxy fatty acids.Structures of all metabolites were suggested by 1H nuclear magnetic resonance and by infrared and mass spectrum.The results showed that the hydroxylation stereospecificity happened at the cis-9 double bond with other position unaffected.
1994, 5(7): 577-580
Abstract:
The dihydric dithioketenes 3a-c obtained by 1,2-addition of methallyl Grignard reagent to bis(alkylthio) methylidene derivatives of dimedone 2a-c were converted to the cycloaromatization product 4 assisted by boron trifluoride etherate.When this reaction was performed in methanol,the substitution-cycloaromatization product 5 was obtained as by-product from 3c.To this cycloaromatization reaction,the reactivity order dimethylthio > 1,3-propylenedithio > 1,2-ethylenedithio carbon cation was established by the yields from 3a-c to 4.An intramolecular a1,a1 reaction pattern was developed by experiment.
The dihydric dithioketenes 3a-c obtained by 1,2-addition of methallyl Grignard reagent to bis(alkylthio) methylidene derivatives of dimedone 2a-c were converted to the cycloaromatization product 4 assisted by boron trifluoride etherate.When this reaction was performed in methanol,the substitution-cycloaromatization product 5 was obtained as by-product from 3c.To this cycloaromatization reaction,the reactivity order dimethylthio > 1,3-propylenedithio > 1,2-ethylenedithio carbon cation was established by the yields from 3a-c to 4.An intramolecular a1,a1 reaction pattern was developed by experiment.
1994, 5(7): 581-584
Abstract:
In present study,an organic compound,DDSi,was found to cleave peptidyl Wang-resin linker efficiently.The yields and purities of free peptides were comparable with products released by TFA,the conventional procedure.
In present study,an organic compound,DDSi,was found to cleave peptidyl Wang-resin linker efficiently.The yields and purities of free peptides were comparable with products released by TFA,the conventional procedure.
1994, 5(7): 585-586
Abstract:
Based on an empirical potential,we have performed calculations of bond lengths of bucky-balls C60, C240, C540, AND C960.Bond length of a monolayer graphite,conridered as an extremely large bucky-ball,has also been calculated.The calculated bond length monotonously decreases with increaring bucky-ball rize,and smoothly connects with the corresponding value of the monolayer graphite.
Based on an empirical potential,we have performed calculations of bond lengths of bucky-balls C60, C240, C540, AND C960.Bond length of a monolayer graphite,conridered as an extremely large bucky-ball,has also been calculated.The calculated bond length monotonously decreases with increaring bucky-ball rize,and smoothly connects with the corresponding value of the monolayer graphite.
1994, 5(7): 587-590
Abstract:
Two cationic carbocyanine were bound to the Si surface through halogenating alcohoiysis,which are characterized by SERS and XPS techniques.The measurement of spectral response and surface photovoltage of dye-bonded Si wafers indicates that Si can be sensitized by bond-dyes,and the Si-dyes have photovoltaic effect.
Two cationic carbocyanine were bound to the Si surface through halogenating alcohoiysis,which are characterized by SERS and XPS techniques.The measurement of spectral response and surface photovoltage of dye-bonded Si wafers indicates that Si can be sensitized by bond-dyes,and the Si-dyes have photovoltaic effect.
1994, 5(7): 591-592
Abstract:
A novel sesquiterpene (1) was isolated from Cremanthodium ellisii Kitam.The structure was elucidated by spectroscopic methods and 2D-NMR techniques.
A novel sesquiterpene (1) was isolated from Cremanthodium ellisii Kitam.The structure was elucidated by spectroscopic methods and 2D-NMR techniques.
1994, 5(7): 593-596
Abstract:
From the EtOAc extract of the underground part of notopterygium incisum Ting.,three new furocoumarins,5-[(2E)-3,7-dimethyl-5-ethyloxy-2,6-octadienyloxy]psoralen named ethylnotopterol (A),5-[(2E,5E)-3,7-dimethyl-7-[(1-ethyloxy)-2,5-octadienyloxy]psoralen named notoptolide (B) and 5-[(2E)-3,7-dimethyl-5,6-epoxy-2,7-octadienyloxy]psoralen named anhydronotoptoloxide (C),were isolated.
From the EtOAc extract of the underground part of notopterygium incisum Ting.,three new furocoumarins,5-[(2E)-3,7-dimethyl-5-ethyloxy-2,6-octadienyloxy]psoralen named ethylnotopterol (A),5-[(2E,5E)-3,7-dimethyl-7-[(1-ethyloxy)-2,5-octadienyloxy]psoralen named notoptolide (B) and 5-[(2E)-3,7-dimethyl-5,6-epoxy-2,7-octadienyloxy]psoralen named anhydronotoptoloxide (C),were isolated.
1994, 5(7): 597-600
Abstract:
A specific example is given to show that high performance capillary electrophoresis can serve as a simple and effective method for the moniforing of an electrochemical oxidation reaction of nuclear fast red.
A specific example is given to show that high performance capillary electrophoresis can serve as a simple and effective method for the moniforing of an electrochemical oxidation reaction of nuclear fast red.
1994, 5(7): 601-602
Abstract:
A flow-through electrochemical measurement system for detecting photogenerated species in solution has been developed.The minimal detecting limit of species life-time can reach 0.1ms in this measurement system.The result of TiO2 electrode showed that the system was reliable and convenient.
A flow-through electrochemical measurement system for detecting photogenerated species in solution has been developed.The minimal detecting limit of species life-time can reach 0.1ms in this measurement system.The result of TiO2 electrode showed that the system was reliable and convenient.
1994, 5(7): 603-604
Abstract:
The trivanadium-substituted heteropolytungstates have been synthesized from their lacunary precursor α-Na9GaW9O40H2.183W NMR spectrum of the title anion consists of two lines as expected for the Cav structure of the trisubstituted A-type Keggin anion.
The trivanadium-substituted heteropolytungstates have been synthesized from their lacunary precursor α-Na9GaW9O40H2.183W NMR spectrum of the title anion consists of two lines as expected for the Cav structure of the trisubstituted A-type Keggin anion.
1994, 5(7): 605-608
Abstract:
The optimized geometries and the electronic structures of Cu2 and Cu3 were studied by DV-Xα method.The result shows the bond length of the diatomic system is 2.50 Å which has a little difference with the experiment but it is in agreement with other theoretical methods such as CI,RESCF.In this investigation we find two nearly-degenerate candidates for the ground state of triatomic system,that the linear geometry state is slightly more stable than the bent isosceles triangular structure(2B2).The result is in good agreement with the ESR spectroscopy obtained by Howard.The difference of energy levels of diatomic system was calculated for the measurement of the orbital interactions of the Cu(4s) and Cu(3d).The total densities of the states of triatomic system are presented to show the electronic structure varying with angle 2θ.
The optimized geometries and the electronic structures of Cu2 and Cu3 were studied by DV-Xα method.The result shows the bond length of the diatomic system is 2.50 Å which has a little difference with the experiment but it is in agreement with other theoretical methods such as CI,RESCF.In this investigation we find two nearly-degenerate candidates for the ground state of triatomic system,that the linear geometry state is slightly more stable than the bent isosceles triangular structure(2B2).The result is in good agreement with the ESR spectroscopy obtained by Howard.The difference of energy levels of diatomic system was calculated for the measurement of the orbital interactions of the Cu(4s) and Cu(3d).The total densities of the states of triatomic system are presented to show the electronic structure varying with angle 2θ.
1994, 5(7): 609-612
Abstract:
In this paper,the total energies and the density of the states of triatomic systems of Cu.Ag.and Au were calculated by discret-variational Xα method.Furthermore,the optimized geometry of triatomic copper,silver,and gold clusters were obtained.The results showed that the optimized geometry of Cu3 was different from that of Ag3.and Au3.Cu3 cluster has two nearly-degenerate candidates for the ground state.Ag3 and Au3 clusters have bent isosceles triangular structure only.The ground configuration for the triatomic clusters is 7a125b21,and the ground state is 2B2.The present evidences are in agreement results with the experimental and with those by other complex theoretical method.
In this paper,the total energies and the density of the states of triatomic systems of Cu.Ag.and Au were calculated by discret-variational Xα method.Furthermore,the optimized geometry of triatomic copper,silver,and gold clusters were obtained.The results showed that the optimized geometry of Cu3 was different from that of Ag3.and Au3.Cu3 cluster has two nearly-degenerate candidates for the ground state.Ag3 and Au3 clusters have bent isosceles triangular structure only.The ground configuration for the triatomic clusters is 7a125b21,and the ground state is 2B2.The present evidences are in agreement results with the experimental and with those by other complex theoretical method.
1994, 5(7): 613-614
Abstract:
Consecutive reaction between two solids,CuCl2.2H2O and 2,2'-bipyridyl in 1:2 molar ratio proceed in two steps:the salt first converts to the mediate,then the mediate turns to the final product.
Consecutive reaction between two solids,CuCl2.2H2O and 2,2'-bipyridyl in 1:2 molar ratio proceed in two steps:the salt first converts to the mediate,then the mediate turns to the final product.
1994, 5(7): 615-616
Abstract:
EPR spectra were measured at 77K for two tailed porphyrin iron(Ⅲ) complexee,5-[o-(1-imidazolyl)butaxyl]phenyl-10,15,20-triphenylporphyrinatairon(Ⅲ) chloride[Mo-ImBPTPPFe(Ⅲ)Cl]and δ-[p-[4-(m-pyridyloxy)butoxyl]phenyl]-10,16,20-triphenylporphyrinatoiron(Ⅲ)chloride[p-PyBPTPPFe(Ⅲ)Cl,and their adducts with imidazole or pyridine,the crystal field parameters of these adducts were calculated from g values.The 1H NMB and visible spectra of these adducts are compared with each other.Form these data,the novel coordination mode of terminal imidaxole in o-ImBPTPPFe(Ⅲ)Cl system were identified.
EPR spectra were measured at 77K for two tailed porphyrin iron(Ⅲ) complexee,5-[o-(1-imidazolyl)butaxyl]phenyl-10,15,20-triphenylporphyrinatairon(Ⅲ) chloride[Mo-ImBPTPPFe(Ⅲ)Cl]and δ-[p-[4-(m-pyridyloxy)butoxyl]phenyl]-10,16,20-triphenylporphyrinatoiron(Ⅲ)chloride[p-PyBPTPPFe(Ⅲ)Cl,and their adducts with imidazole or pyridine,the crystal field parameters of these adducts were calculated from g values.The 1H NMB and visible spectra of these adducts are compared with each other.Form these data,the novel coordination mode of terminal imidaxole in o-ImBPTPPFe(Ⅲ)Cl system were identified.
1994, 5(7): 617-618
Abstract:
A new ion-pair complex[Mo(dtc)4] [Sm(dtc)4]was synthesized here.Its molecular structure and crystal structure was determined through X-ray Diffraction method.
A new ion-pair complex[Mo(dtc)4] [Sm(dtc)4]was synthesized here.Its molecular structure and crystal structure was determined through X-ray Diffraction method.
1994, 5(7): 619-622
Abstract:
Ba-K-Bi-O and Ba-K-M-Bi-O(M=Rb,Pb and La) single crystals were prepared using the eleotrocrystallization method.Ihe resulting crystalline materials were characterised by XPS,XRD and magnetic method.
Ba-K-Bi-O and Ba-K-M-Bi-O(M=Rb,Pb and La) single crystals were prepared using the eleotrocrystallization method.Ihe resulting crystalline materials were characterised by XPS,XRD and magnetic method.
1994, 5(7): 623-626
Abstract:
The behavior of light-induced charge transfer and photovoltaic properties of nanocrystalline Nd2O3 were investigated with SPS and FMSPS.It was found that the SPS shows two peaks at 330 nm(P1)and 380 nm(P2)in the UV-vis range.The observed spectral features can be explained in terms of charge transfer and interband transition.
The behavior of light-induced charge transfer and photovoltaic properties of nanocrystalline Nd2O3 were investigated with SPS and FMSPS.It was found that the SPS shows two peaks at 330 nm(P1)and 380 nm(P2)in the UV-vis range.The observed spectral features can be explained in terms of charge transfer and interband transition.
1994, 5(7): 627-630
Abstract:
Nanocrystalline CdS films of different sizes and thicknesses were electrochemically prepared on ITO.The films exhibit size quantization effects,manifested by large blue-shifts in their optical absorption spectra.The Surface Photovoltaic Spectroscopy (SPS) of these filnis shows particular photovoltaic behavior.It is for the first time to observe size quantization effects and a blue shift in the SPS of CdS films.
Nanocrystalline CdS films of different sizes and thicknesses were electrochemically prepared on ITO.The films exhibit size quantization effects,manifested by large blue-shifts in their optical absorption spectra.The Surface Photovoltaic Spectroscopy (SPS) of these filnis shows particular photovoltaic behavior.It is for the first time to observe size quantization effects and a blue shift in the SPS of CdS films.
1994, 5(7): 631-634
Abstract:
Ni-containing carbon films were prepared by rf glow discharge decomposition of methane and nickel carbonyl.The deposited films contained C,Ni,H,O and small amounts of N.Nickel existed in forms of metallic Ni and Ni2O3.The oxidation of nickel mainly occurred on film surface.With lower Ni contents,the film maintained the structure of DLC film-With the increase of Ni content,the films showed some crystalline features of Ni and Ni2O3.
Ni-containing carbon films were prepared by rf glow discharge decomposition of methane and nickel carbonyl.The deposited films contained C,Ni,H,O and small amounts of N.Nickel existed in forms of metallic Ni and Ni2O3.The oxidation of nickel mainly occurred on film surface.With lower Ni contents,the film maintained the structure of DLC film-With the increase of Ni content,the films showed some crystalline features of Ni and Ni2O3.
1994, 5(7): 635-636
Abstract:
A new chiral liquid crystal[4'-(2-chloro-4-methyl-pentanoyloxy)]-phenyl 2-cyano-3-(4'-a-heptanoxypkenyl)propenoate (CMPPCHPP) was synthesized.The compound was characterized by IR,1HNMR,clemental analysis.The liquid crystalline phase transition was studled by optical polarized micrography.The title liquid crystal compound end induce cholenteric pitch in nematic LC (B7902),the pitch in 12 μm at 283K.
A new chiral liquid crystal[4'-(2-chloro-4-methyl-pentanoyloxy)]-phenyl 2-cyano-3-(4'-a-heptanoxypkenyl)propenoate (CMPPCHPP) was synthesized.The compound was characterized by IR,1HNMR,clemental analysis.The liquid crystalline phase transition was studled by optical polarized micrography.The title liquid crystal compound end induce cholenteric pitch in nematic LC (B7902),the pitch in 12 μm at 283K.
1994, 5(7): 637-638
Abstract:
The silicon-oxygen-silicon bond in bissilyl ethers was broken by magnesium diethoxide and new silicon-oxygen-earbon bond was formed.
The silicon-oxygen-silicon bond in bissilyl ethers was broken by magnesium diethoxide and new silicon-oxygen-earbon bond was formed.
1994, 5(7): 639-642
Abstract:
Hydrothermal crystallization of an aluminophosphate molecular sieve (AlPO4-12) has first been carried out from non-aqueous systems in the presence of templating agent,with the molar composition of the starting gel as 1.0Al2O3:5.0P2O5:10ethylenediamine:180ethylene glycol.Aluminum triisopropoxide and phosphorous acid(85 wt% H3PO4)were used exclusively as aourcea for aluminum and phosphorous.The product has been characterized by means of X-ray powder diffraction (XRD),scanning electron microscopy (SEM),infrared (IR)spectrum,differential thermal analysis (DTA),thermogravimetric analysis (TG),etc.
Hydrothermal crystallization of an aluminophosphate molecular sieve (AlPO4-12) has first been carried out from non-aqueous systems in the presence of templating agent,with the molar composition of the starting gel as 1.0Al2O3:5.0P2O5:10ethylenediamine:180ethylene glycol.Aluminum triisopropoxide and phosphorous acid(85 wt% H3PO4)were used exclusively as aourcea for aluminum and phosphorous.The product has been characterized by means of X-ray powder diffraction (XRD),scanning electron microscopy (SEM),infrared (IR)spectrum,differential thermal analysis (DTA),thermogravimetric analysis (TG),etc.
