Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-bip...Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-biphenyl(di-BHA).The yield of reaction attained 95% and the selectivity for BBDQ was 100%.The single-crystal X-ray diffraction analysis reveals that the dihedral angle between two rings(benzene rings for di-BHA and quinone rings for BBDQ)changes from 89.8 to 45.3o,indicating the steric hindrance effects of methyl disappear in the oxidation process.The crystal structures of di-BHA and BBDQ are further confirmed by their spectral characterizations.The probable mechanism for this oxidation process is also discussed.展开更多
A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots o...A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots of Stellera chamaejasme L. together with known chamaechromone. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.展开更多
A new flavonoid glycoside, 5, 7-dihydroxy-4'-methoxyflavonoid 7-Q-[6-O-(4-O-acetyl-alpha-L-rhamnosyl)-3-O-beta-D-glucosyl]-6-O-acetyl-beta-D-glucoside was isolated from Thalictrum przewalskii. Its structure was de...A new flavonoid glycoside, 5, 7-dihydroxy-4'-methoxyflavonoid 7-Q-[6-O-(4-O-acetyl-alpha-L-rhamnosyl)-3-O-beta-D-glucosyl]-6-O-acetyl-beta-D-glucoside was isolated from Thalictrum przewalskii. Its structure was determined on basis of spectroscopic evidences.展开更多
Two hydrates of sodium 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate ([Na(H2O)](C17H13O6SO3)2H2O, 1) and nickel 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate ([Ni(H2O)6](C17H13O6SO3)24H2O, ...Two hydrates of sodium 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate ([Na(H2O)](C17H13O6SO3)2H2O, 1) and nickel 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate ([Ni(H2O)6](C17H13O6SO3)24H2O, 2) were syn-thesized and characterized by IR, 1H NMR and X-ray diffraction analyses. The hydrate 1 crystallizes in the mono-clinic system, space group P2(1) with a=0.8201(9) nm, b=0.8030(8) nm, c=1.5361(16) nm, =102.052(12), V=0.9893(18) nm3, Dc=1.579 g/cm3, Z=2, =0.252 nm-1, F(000)=488, R=0.0353, wR=0.0873. The hydrate 2 belongs to triclinic system, space group P-1 with a=0.7411(3) nm, b=0.8333(3) nm, c=1.7448(7) nm, a=86.361(6), 撸?6.389(5), ?=88.999(3), V=1.0731(7) nm3, Dc=1.587 g/cm3, Z=1, =0.649 mm-1, F(000)=534. In the structure of 1, the sodium cation is coordinated by six oxygen atoms and two adjacent ones are bridged by three oxygen atoms to form an octahedron chain. The C—H…p hydrogen bonds exist between two isoflavone molecules in the structure of 2. Meanwhile, hydrogen bonds in two compounds, link themselves to assemble two three-dimensional network structures, respectively.展开更多
基金supported by the 973 Program (2005CB623607)the National Natural Science Foundation of China (No.20771061)the scientific program 2008BAE64B09
文摘Use of free air as oxidant and copper(II)chloride as catalyst,3,3'-di-tert-butylbi-phenyl-2,5,2',5'-diquinone(BBDQ)was prepared via catalytic oxidation of 2,2'-dihydroxy-3,3'-di-tert-butyl-5,5'-dimethoxy-biphenyl(di-BHA).The yield of reaction attained 95% and the selectivity for BBDQ was 100%.The single-crystal X-ray diffraction analysis reveals that the dihedral angle between two rings(benzene rings for di-BHA and quinone rings for BBDQ)changes from 89.8 to 45.3o,indicating the steric hindrance effects of methyl disappear in the oxidation process.The crystal structures of di-BHA and BBDQ are further confirmed by their spectral characterizations.The probable mechanism for this oxidation process is also discussed.
文摘A new chromone derivative, 3-[1- (2, 4, 6-trihydroxyphenyl) 3-di-(4-hydroxyphenyl) 1-propanone-2-yl] 5,7-dihydroxy-8-di(4-hydroxyphenyl)methyl-4H-1-benzopyran-4-one, named as isomohsenone was isolated from the roots of Stellera chamaejasme L. together with known chamaechromone. Its structure was determined by the analysis of MS and NMR data, especially 2D NMR spectra.
文摘A new flavonoid glycoside, 5, 7-dihydroxy-4'-methoxyflavonoid 7-Q-[6-O-(4-O-acetyl-alpha-L-rhamnosyl)-3-O-beta-D-glucosyl]-6-O-acetyl-beta-D-glucoside was isolated from Thalictrum przewalskii. Its structure was determined on basis of spectroscopic evidences.
基金the Natural Science Foundation of Shaanxi Province (No. 2001K11-G5).
文摘Two hydrates of sodium 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate ([Na(H2O)](C17H13O6SO3)2H2O, 1) and nickel 5,7-dihydroxy-6,4'-dimethoxyisoflavone-3'-sulfonate ([Ni(H2O)6](C17H13O6SO3)24H2O, 2) were syn-thesized and characterized by IR, 1H NMR and X-ray diffraction analyses. The hydrate 1 crystallizes in the mono-clinic system, space group P2(1) with a=0.8201(9) nm, b=0.8030(8) nm, c=1.5361(16) nm, =102.052(12), V=0.9893(18) nm3, Dc=1.579 g/cm3, Z=2, =0.252 nm-1, F(000)=488, R=0.0353, wR=0.0873. The hydrate 2 belongs to triclinic system, space group P-1 with a=0.7411(3) nm, b=0.8333(3) nm, c=1.7448(7) nm, a=86.361(6), 撸?6.389(5), ?=88.999(3), V=1.0731(7) nm3, Dc=1.587 g/cm3, Z=1, =0.649 mm-1, F(000)=534. In the structure of 1, the sodium cation is coordinated by six oxygen atoms and two adjacent ones are bridged by three oxygen atoms to form an octahedron chain. The C—H…p hydrogen bonds exist between two isoflavone molecules in the structure of 2. Meanwhile, hydrogen bonds in two compounds, link themselves to assemble two three-dimensional network structures, respectively.