R, 6S)-6-Acetoxyhexadecan-5-olide 1, a natural mosquito attractant pheromone, was synthesized from readily available aldehyde 2 and cyclopentanone 3 using L-proline-catalyzed asymmetric aldol reaction as the key step.
The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring inter...The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.展开更多
Two new sesquiterpene lactone glycosides were isolated from the whole plant of Sonchus transcaspicus. Their structures were elucidated as 1β-O-β-D-glucopyranosy-5α, 6β H-eudesma-3-en-12, 6α-olide and 1β-O-β...Two new sesquiterpene lactone glycosides were isolated from the whole plant of Sonchus transcaspicus. Their structures were elucidated as 1β-O-β-D-glucopyranosy-5α, 6β H-eudesma-3-en-12, 6α-olide and 1β-O-β-D-glucopyranosy-15-O-(p-hydroxylphenylacetate)-5α, 6β H-eudesma-3, 11(13)-dien-12, 6α-olide by spectral methods (HRMS, 1D and 2D NMR).展开更多
A new neolignan glycoside named armaoside (1) was isolated from the whole plant of Pedicularis armata Maxim. Its structure was elucidated by spectroscopic and chemical methods. Antibacterial assay showed that it has m...A new neolignan glycoside named armaoside (1) was isolated from the whole plant of Pedicularis armata Maxim. Its structure was elucidated by spectroscopic and chemical methods. Antibacterial assay showed that it has moderately antibacterial activities against Eschecichia coli, Bacillus subtilis and Staphylococcus aureus.展开更多
An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids: the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathy...An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids: the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathyrus sativus extracts using the HPLC system after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-Cl). However, it is more worthy of noting that this paper also describes a new extraction method using 0.2 mol/L HClO4. The new method has some advantages: shorter extraction-time, simultaneous extraction of free amino acids and polyamines, better inhibiting the isomerization of β-ODAP to α-ODAP, and so on.展开更多
Diarylheptanoids, most of which appearing in the areas of anti-inflammatory, anti-oxidative, superoxide scavenging and anti-hepatotoxic effects, constitute a distinct group of metabolites of natural plants characteriz...Diarylheptanoids, most of which appearing in the areas of anti-inflammatory, anti-oxidative, superoxide scavenging and anti-hepatotoxic effects, constitute a distinct group of metabolites of natural plants characterized by two aromatic rings linked by a linear seven aliphatic chain. We have investigated this kind of compounds and made some progresslit.展开更多
Regio and stereoselective synthesis of substituted dihydrofurans were accomplished by eeric ammonium nitrate mediated oxidative cycloaddition of 1,3-dicarbonyls to β-aryl-α,β-unsaturated ketones in moderate yields.
A concise and efficient total synthesis of (-)-umbelactone 1, an occurring γ- hydroxymethyl-α, β-butenolide from Memycelon umbelatum Burm, is described. The synthesis features the use of a ring closing metathesis s...A concise and efficient total synthesis of (-)-umbelactone 1, an occurring γ- hydroxymethyl-α, β-butenolide from Memycelon umbelatum Burm, is described. The synthesis features the use of a ring closing metathesis strategy.展开更多
An effective approach for the construction of the decalin ring skeleton of labdane diterpenoids was developed based on a key biomimetic cationic polyene cyclization of an epoxy allylsilane precursor. The synthetic a...An effective approach for the construction of the decalin ring skeleton of labdane diterpenoids was developed based on a key biomimetic cationic polyene cyclization of an epoxy allylsilane precursor. The synthetic approach demonstrated here would be useful in the enantioselective and diastereoselective total synthesis of natural labdane diterpenoids in general.展开更多
Chemical investigation of Erigeron annus afforded two new eudesmenes, which were identified as 1β, 5α-dihydroxyeudesma-4(15)-en (1) and 1β, 7α-dihydroxyeudesma-4(15)-en (2). Their structures were established by ...Chemical investigation of Erigeron annus afforded two new eudesmenes, which were identified as 1β, 5α-dihydroxyeudesma-4(15)-en (1) and 1β, 7α-dihydroxyeudesma-4(15)-en (2). Their structures were established by spectroscopic methods including 2D NMR experiments.展开更多
Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facil...Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.展开更多
A novel triterpenoid, D:B-friedoursane-3α, 16α-dihydroxy-7α, 8α-epoxy-5(10)-ene, named petatrichol A, was isolated from the roots of Petasites tricholobus Franch.. Its structure was elucidated by spectroscopic met...A novel triterpenoid, D:B-friedoursane-3α, 16α-dihydroxy-7α, 8α-epoxy-5(10)-ene, named petatrichol A, was isolated from the roots of Petasites tricholobus Franch.. Its structure was elucidated by spectroscopic methods, especially 2DNMR techniques.展开更多
The solvent-free mechanochemical reaction and the liquid-phase reaction of C60 with ethyl 2-diazopropionate prepared in situ or preformed from alanine ethyl ester hydrochloride and sodium nitrite have been investigate...The solvent-free mechanochemical reaction and the liquid-phase reaction of C60 with ethyl 2-diazopropionate prepared in situ or preformed from alanine ethyl ester hydrochloride and sodium nitrite have been investigated. Methanofullerene 1 and fulleroids 2 and 3 from these reactions were obtained, meanwhile the pyrazoline intermediate was not observed. Fulleroids 2 and 3 can be converted to methanofullerene 1 in refluxing toluene.展开更多
A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γ- eudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, th...A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γ- eudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.展开更多
An asymmetric total synthesis of mansonone P and R were achieved, in whichintroduction of hydroxy substituent at position 2 was performed by Sharpless dihydroxylation ofsily enol ether.
The crystal structure of 4-phenyl-5-(1-t-butyl-5-methyl-4-pyrazolyl)-1,2,4-triazol- 3-thione 5 (C16H19N5S, Mr = 313.42) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclin...The crystal structure of 4-phenyl-5-(1-t-butyl-5-methyl-4-pyrazolyl)-1,2,4-triazol- 3-thione 5 (C16H19N5S, Mr = 313.42) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 6.680(2), b = 27.44(1), c = 9.388(4) ? b = 106.738(6), V = 1648(1) 3, Z = 4, Dc = 1.263 g/cm3, m = 0.200 mm-1, F(000) = 664, R = 0.0608 and wR = 0.1176. The results confirmed that 5 can be assigned to the thione tautomeric form.展开更多
An alternative route for the synthesis of (-)-10-epi-α-cyperone 1 starting from (+)- dihydrocarvone 2 is described by using an asymmetric Michael addition as a key step. The route features more efficiently and can be...An alternative route for the synthesis of (-)-10-epi-α-cyperone 1 starting from (+)- dihydrocarvone 2 is described by using an asymmetric Michael addition as a key step. The route features more efficiently and can be performed in large scale.展开更多
文摘R, 6S)-6-Acetoxyhexadecan-5-olide 1, a natural mosquito attractant pheromone, was synthesized from readily available aldehyde 2 and cyclopentanone 3 using L-proline-catalyzed asymmetric aldol reaction as the key step.
文摘The reaction of nitrosonium (NO+) with Schiff bases produced diazonium salts and aldehydes in good yield. The reaction is assumed to be an electrophilic reaction of nitrosonium with imines via a four-member ring intermediate.
基金supported by the NNSFC(No.20372029 and No.20021001-QT Program)
文摘Two new sesquiterpene lactone glycosides were isolated from the whole plant of Sonchus transcaspicus. Their structures were elucidated as 1β-O-β-D-glucopyranosy-5α, 6β H-eudesma-3-en-12, 6α-olide and 1β-O-β-D-glucopyranosy-15-O-(p-hydroxylphenylacetate)-5α, 6β H-eudesma-3, 11(13)-dien-12, 6α-olide by spectral methods (HRMS, 1D and 2D NMR).
文摘A new neolignan glycoside named armaoside (1) was isolated from the whole plant of Pedicularis armata Maxim. Its structure was elucidated by spectroscopic and chemical methods. Antibacterial assay showed that it has moderately antibacterial activities against Eschecichia coli, Bacillus subtilis and Staphylococcus aureus.
基金This work was supported by NKBRSF Project(G2000018603)the National Natural Science Foundation of China(No.30270965).
文摘An assay is presented for simultaneously determining 5 biogenic amines and the major non-protein amino acids: the toxin β-N-oxalyl-L-α,β-diaminopropanoic acid (β-ODAP), its isomer α-ODAP and homoarginine in Lathyrus sativus extracts using the HPLC system after derivatization with para-nitrobenzyloxycarbonyl chloride (PNZ-Cl). However, it is more worthy of noting that this paper also describes a new extraction method using 0.2 mol/L HClO4. The new method has some advantages: shorter extraction-time, simultaneous extraction of free amino acids and polyamines, better inhibiting the isomerization of β-ODAP to α-ODAP, and so on.
文摘Diarylheptanoids, most of which appearing in the areas of anti-inflammatory, anti-oxidative, superoxide scavenging and anti-hepatotoxic effects, constitute a distinct group of metabolites of natural plants characterized by two aromatic rings linked by a linear seven aliphatic chain. We have investigated this kind of compounds and made some progresslit.
文摘Regio and stereoselective synthesis of substituted dihydrofurans were accomplished by eeric ammonium nitrate mediated oxidative cycloaddition of 1,3-dicarbonyls to β-aryl-α,β-unsaturated ketones in moderate yields.
基金financially supported by the National Natural Science Foundation of China(Grant No.20072012)the Special Research Grant for Doctoral Sites in Chinese Universities(Grant No.20010730001).
文摘A concise and efficient total synthesis of (-)-umbelactone 1, an occurring γ- hydroxymethyl-α, β-butenolide from Memycelon umbelatum Burm, is described. The synthesis features the use of a ring closing metathesis strategy.
基金financial support from the National Outstanding Youth Fund(No.29925204)
文摘An effective approach for the construction of the decalin ring skeleton of labdane diterpenoids was developed based on a key biomimetic cationic polyene cyclization of an epoxy allylsilane precursor. The synthetic approach demonstrated here would be useful in the enantioselective and diastereoselective total synthesis of natural labdane diterpenoids in general.
基金supported by the NNSFC(No.20372029 and No.20021001-QT Program)
文摘Chemical investigation of Erigeron annus afforded two new eudesmenes, which were identified as 1β, 5α-dihydroxyeudesma-4(15)-en (1) and 1β, 7α-dihydroxyeudesma-4(15)-en (2). Their structures were established by spectroscopic methods including 2D NMR experiments.
基金This work was financially supported by the National Natural Science Foundation (DistinguishedYouth Fund 29925204) Fok Ying Tung Education Foundaiton (Fund 71012).
文摘Methylenedioxyphenyl unit displays a significant stereoelectronic effect in some key transformations in the total synthesis of cephalotaxine. The ring-strain of methylenedioxy ring may account for some important facile ring-skeleton rearrangements.
基金This project was suppoaed by the NNSFC(No．2997201)
文摘A novel triterpenoid, D:B-friedoursane-3α, 16α-dihydroxy-7α, 8α-epoxy-5(10)-ene, named petatrichol A, was isolated from the roots of Petasites tricholobus Franch.. Its structure was elucidated by spectroscopic methods, especially 2DNMR techniques.
文摘The solvent-free mechanochemical reaction and the liquid-phase reaction of C60 with ethyl 2-diazopropionate prepared in situ or preformed from alanine ethyl ester hydrochloride and sodium nitrite have been investigated. Methanofullerene 1 and fulleroids 2 and 3 from these reactions were obtained, meanwhile the pyrazoline intermediate was not observed. Fulleroids 2 and 3 can be converted to methanofullerene 1 in refluxing toluene.
基金This work was financially supported by the National Natural Science Foundation of China(No.20272021).
文摘A facile synthetic route to two seco-eudesmane, 4, 5-dioxo-10-epi-4, 5-seco-γ- eudesmane (1) and 4, 5-dioxo-10-epi-4, 5-seco-γ-eudesmol (2) from (+)-dihydrocarvone has been described. Avoiding expensive reagents, this highly economic method especially suits for the synthesis of 4, 5-seco-eudesman-type and ophianon-type sesquiterpenes with a double bond at position 11 and 12.
基金This work was supported by NNSFC(QT program)NNSFC(20372026)+1 种基金SRF for ROCS.SEM,Gansu Science Foundation(No,YS031-A21-001)Lanzhou University Foundation(No.5715220101).
文摘An asymmetric total synthesis of mansonone P and R were achieved, in whichintroduction of hydroxy substituent at position 2 was performed by Sharpless dihydroxylation ofsily enol ether.
基金The project was supported by the Natural Science Foundation of Shandong Province (No. Y2003B01) and NNSFC (No. 20172031)
文摘The crystal structure of 4-phenyl-5-(1-t-butyl-5-methyl-4-pyrazolyl)-1,2,4-triazol- 3-thione 5 (C16H19N5S, Mr = 313.42) has been determined by single-crystal X-ray diffraction analysis. The crystal belongs to monoclinic, space group P21/c with a = 6.680(2), b = 27.44(1), c = 9.388(4) ? b = 106.738(6), V = 1648(1) 3, Z = 4, Dc = 1.263 g/cm3, m = 0.200 mm-1, F(000) = 664, R = 0.0608 and wR = 0.1176. The results confirmed that 5 can be assigned to the thione tautomeric form.
文摘An alternative route for the synthesis of (-)-10-epi-α-cyperone 1 starting from (+)- dihydrocarvone 2 is described by using an asymmetric Michael addition as a key step. The route features more efficiently and can be performed in large scale.
