The reaction of a series of hydroxy-substituted polycyclic aromatic hydrocarbons(PAHs)with nitric oxide containing trace O 2 was carried out in CH 2Cl 2 at room temperature. The products identified by IR, NMR and HRMS...The reaction of a series of hydroxy-substituted polycyclic aromatic hydrocarbons(PAHs)with nitric oxide containing trace O 2 was carried out in CH 2Cl 2 at room temperature. The products identified by IR, NMR and HRMS indicate that the mono nitration at para- or ortho-position with respect to hydroxy group on the benzene ring occurred regioselectively. The reactions are assumed to be initiated by single electron transfer and the reaction intermediates may be resonance stabilized phenoxy-like radicals.展开更多
The first total synthesis of （+）-5α-hydroxy-isopterocarpolone （1）, an oxygenated eudesmane isolated from Chinese folk medicine Artemisia eriopoda, starting from （+）-dihydrocarvone（2） was described. Compound 4...The first total synthesis of （+）-5α-hydroxy-isopterocarpolone （1）, an oxygenated eudesmane isolated from Chinese folk medicine Artemisia eriopoda, starting from （+）-dihydrocarvone（2） was described. Compound 4 was stereoselectively prepared from compound 2 in three steps according to reference-. The treatment of tosylhydrazone 5, which was formed via the reaction of compound 4 and TsNHNH2 catalyzed by BF3-5Et2O, with an excess of n-butyllithium gave triene 6. Oxidation of triene 6 with singlet oxygen afforded the desired endo-peroxide 7 as a single product. Reductive cleavage of peroxide 7 with K2CO3 gave α-rotunol 3, a natural eudesmane firstly isolated in 1969. Hydrolysis of α-rotunol 3 with 10% sulfuric acid afforded （+）-5α-hydroxy-isopterocarpolone （1）. The structures of all the compounds were confirmed by IR, MS and NMR spectra.展开更多
(±)-1-Methyl-7-oxabicyclo[2.2.1]heptan-2-one (1) is a versatile chiral building block for terpenoids. It could be applied in total synthesis of eudesmanes, agarofurans and norcarotenoids. Compound (±)-1 was ...(±)-1-Methyl-7-oxabicyclo[2.2.1]heptan-2-one (1) is a versatile chiral building block for terpenoids. It could be applied in total synthesis of eudesmanes, agarofurans and norcarotenoids. Compound (±)-1 was reduced to alcohol (±)-2. Compound (±)-2 was esterified with commercial available optically pure (S)-(+)-mandelic acid. The diastereomeric ester mixture was separated with preparative HPLC method. After oxidation of the saponified products of diastereomeric ester (+)-4 and (+)-5 respectively, both optically pure enantiomers of compound 1 were prepared for the first time in four steps with an overall yield of 70%. The absolute configurations of (+)-1 and (-)-1 were determined as (+)-(1R,4S)-1-methyl-7-oxabicyclo[2.2.1] heptan-2-one and (-)-(1S,4R)-1-methyl-7-oxabicyclo[2.2.1] heptan-2-one.展开更多
3-Oxo-11,12,13-trihydroxyeudesm-4-ene(1) was a highly oxygenated natural eudesmane isolated from traditional herbal medicine with an antiphlogostic and spasmolytic activity.For the purpose of pharmacological activity ...3-Oxo-11,12,13-trihydroxyeudesm-4-ene(1) was a highly oxygenated natural eudesmane isolated from traditional herbal medicine with an antiphlogostic and spasmolytic activity.For the purpose of pharmacological activity research on natural product 1 and its derivatives,a facile total synthesis of compound 1 starting from(+)-dihydrocarvone(2) was completed in an overall yield of 24%.The structures of all intermediates and product 1 were confirmed via 1H NMR,13C NMR,MS and IR techniques.The NMR data of compound 1 are in agreement with those of natural products.展开更多
High resolution mass spectrometry was used in positive ion to study the element compositions and MS/MS analysis of Ni2+complexes of 2-hydroxy-4-methoxy-acetophenone schiff base.The result shows that new complexes was ...High resolution mass spectrometry was used in positive ion to study the element compositions and MS/MS analysis of Ni2+complexes of 2-hydroxy-4-methoxy-acetophenone schiff base.The result shows that new complexes was formed in ESI and [NiL1]+,Ni(L2)2 was dissociated in different way.展开更多
基金supported by the National Natural Science Foundation of China(21272033)Innovation Fund of State Key Laboratory of Electronic Thin Films and Integrated Devices,China(CXJJ201104)Beijing National Laboratory for Molecular Sciences,China(BNLMS)~~
文摘The reaction of a series of hydroxy-substituted polycyclic aromatic hydrocarbons(PAHs)with nitric oxide containing trace O 2 was carried out in CH 2Cl 2 at room temperature. The products identified by IR, NMR and HRMS indicate that the mono nitration at para- or ortho-position with respect to hydroxy group on the benzene ring occurred regioselectively. The reactions are assumed to be initiated by single electron transfer and the reaction intermediates may be resonance stabilized phenoxy-like radicals.
文摘The first total synthesis of （+）-5α-hydroxy-isopterocarpolone （1）, an oxygenated eudesmane isolated from Chinese folk medicine Artemisia eriopoda, starting from （+）-dihydrocarvone（2） was described. Compound 4 was stereoselectively prepared from compound 2 in three steps according to reference-. The treatment of tosylhydrazone 5, which was formed via the reaction of compound 4 and TsNHNH2 catalyzed by BF3-5Et2O, with an excess of n-butyllithium gave triene 6. Oxidation of triene 6 with singlet oxygen afforded the desired endo-peroxide 7 as a single product. Reductive cleavage of peroxide 7 with K2CO3 gave α-rotunol 3, a natural eudesmane firstly isolated in 1969. Hydrolysis of α-rotunol 3 with 10% sulfuric acid afforded （+）-5α-hydroxy-isopterocarpolone （1）. The structures of all the compounds were confirmed by IR, MS and NMR spectra.
文摘(±)-1-Methyl-7-oxabicyclo[2.2.1]heptan-2-one (1) is a versatile chiral building block for terpenoids. It could be applied in total synthesis of eudesmanes, agarofurans and norcarotenoids. Compound (±)-1 was reduced to alcohol (±)-2. Compound (±)-2 was esterified with commercial available optically pure (S)-(+)-mandelic acid. The diastereomeric ester mixture was separated with preparative HPLC method. After oxidation of the saponified products of diastereomeric ester (+)-4 and (+)-5 respectively, both optically pure enantiomers of compound 1 were prepared for the first time in four steps with an overall yield of 70%. The absolute configurations of (+)-1 and (-)-1 were determined as (+)-(1R,4S)-1-methyl-7-oxabicyclo[2.2.1] heptan-2-one and (-)-(1S,4R)-1-methyl-7-oxabicyclo[2.2.1] heptan-2-one.
文摘3-Oxo-11,12,13-trihydroxyeudesm-4-ene(1) was a highly oxygenated natural eudesmane isolated from traditional herbal medicine with an antiphlogostic and spasmolytic activity.For the purpose of pharmacological activity research on natural product 1 and its derivatives,a facile total synthesis of compound 1 starting from(+)-dihydrocarvone(2) was completed in an overall yield of 24%.The structures of all intermediates and product 1 were confirmed via 1H NMR,13C NMR,MS and IR techniques.The NMR data of compound 1 are in agreement with those of natural products.
文摘High resolution mass spectrometry was used in positive ion to study the element compositions and MS/MS analysis of Ni2+complexes of 2-hydroxy-4-methoxy-acetophenone schiff base.The result shows that new complexes was formed in ESI and [NiL1]+,Ni(L2)2 was dissociated in different way.
