The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis...The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis. The structures of these compounds were characterized by ^1H NMR, elemental analysis, UV-Vis absorption spectrum and X-ray diffraction analysis. The conformation of O--C--O bridged biphenyl derivatives with varied substitute groups on 6,6＇-position was studied by X-ray crystallography and force-field simulation. The result of calculations by UNIVERSAL 1.02 force field in Cerius2 package（4.6） indicates that dibenzo[d,f][1,3]dioxepine derivatives show twisted conformations and the twisted angle between the phenyl rings is about 40°, which is accordant with the result from crystal structure determination, though the obtained angles in the crystal of dibenzo[d,f][1,3]dioxepine derivatives with the varied substitute groups on 6,6＇-position are shown to be slightly shifted to 40° owing to intermolecular interactions in crystal stacking. DSC studies exhibit that the substitute groups on 6,6＇-position can induce a large variation of endothermic peaks ranging from 80 to 135 ℃. The conjugated polymers based on dibenzo[d,f][1,3]dioxepine derivatives, which have ultraviolet emitting with a quantum efficiency of 10%, were obtained by Yamamoto coupling.展开更多
二苯并-1,3-二氧杂-环辛烷-2-羧酸丙酮肟酯(SYP-185)是沈阳化工研究院正在进行前期开发的除草剂。由二苯并-1,3-二氧杂-环辛烷-2-羧酸经两步反应制得,总收率70%。其结构经红外、核磁共振谱和元素分析确证。标题化合物在100 g a.i./hm2...二苯并-1,3-二氧杂-环辛烷-2-羧酸丙酮肟酯(SYP-185)是沈阳化工研究院正在进行前期开发的除草剂。由二苯并-1,3-二氧杂-环辛烷-2-羧酸经两步反应制得,总收率70%。其结构经红外、核磁共振谱和元素分析确证。标题化合物在100 g a.i./hm2剂量下可防多种杂草;在300 g a.i./hm2对小麦安全。展开更多
In this paper, two new compounds, ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic acid 4 and its ethyl ester 5 were synthesized in good yield with a facile method that has never been reported. The mechanism of this ...In this paper, two new compounds, ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic acid 4 and its ethyl ester 5 were synthesized in good yield with a facile method that has never been reported. The mechanism of this reaction was discussed and the mono-hydroxymethylation of carbonyl compound with two α-hydrogens via Tollens＇ reaction was firstly achieved. Compounds 2-5 were tested for activity of inhibition against glycosidases, among which 5 displays good inhibition of β-glucosidase and α-mannase, respectively.展开更多
Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as （＋）-5-（1,2-dihydroxypentyl）...Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as （＋）-5-（1,2-dihydroxypentyl）-benzene- 1,3-diol and （-）-5-（1,2- dihydroxypentyl）benzene- 1,3-diol.展开更多
A new alkaloid, named 6-（2＇,3＇-dihydroxy-4＇-hydroxymethyl-tetrahydro-furan-1＇-yl）cyclopentadiene[c]pyrrole-1,3-diol, was isolated from the seeds of Castanea mollissima Blume. The structure was elucidated based o...A new alkaloid, named 6-（2＇,3＇-dihydroxy-4＇-hydroxymethyl-tetrahydro-furan-1＇-yl）cyclopentadiene[c]pyrrole-1,3-diol, was isolated from the seeds of Castanea mollissima Blume. The structure was elucidated based on spectroscopic evidence including 2D NMR techniques.展开更多
基金Supported by the National Natural Science Foundation of China(Nos.20125421 and 90101026)the Ministry of Science and Technology of China(No.2002CB6134003)
文摘The twisted aromatics, functional dibenzo[d,f][1,3]dioxepine derivatives were synthesized in high yields from reactions of 5,5＇-dibromo-2,2＇-biphenol with corresponding ketal or ketone compounds under acid catalysis. The structures of these compounds were characterized by ^1H NMR, elemental analysis, UV-Vis absorption spectrum and X-ray diffraction analysis. The conformation of O--C--O bridged biphenyl derivatives with varied substitute groups on 6,6＇-position was studied by X-ray crystallography and force-field simulation. The result of calculations by UNIVERSAL 1.02 force field in Cerius2 package（4.6） indicates that dibenzo[d,f][1,3]dioxepine derivatives show twisted conformations and the twisted angle between the phenyl rings is about 40°, which is accordant with the result from crystal structure determination, though the obtained angles in the crystal of dibenzo[d,f][1,3]dioxepine derivatives with the varied substitute groups on 6,6＇-position are shown to be slightly shifted to 40° owing to intermolecular interactions in crystal stacking. DSC studies exhibit that the substitute groups on 6,6＇-position can induce a large variation of endothermic peaks ranging from 80 to 135 ℃. The conjugated polymers based on dibenzo[d,f][1,3]dioxepine derivatives, which have ultraviolet emitting with a quantum efficiency of 10%, were obtained by Yamamoto coupling.
文摘二苯并-1,3-二氧杂-环辛烷-2-羧酸丙酮肟酯(SYP-185)是沈阳化工研究院正在进行前期开发的除草剂。由二苯并-1,3-二氧杂-环辛烷-2-羧酸经两步反应制得,总收率70%。其结构经红外、核磁共振谱和元素分析确证。标题化合物在100 g a.i./hm2剂量下可防多种杂草;在300 g a.i./hm2对小麦安全。
基金the National Natural Science Foundation of China(20372059)Natural Science Foundation of Henan Province for the financial support(0311020500).
文摘In this paper, two new compounds, ent-16α-hydroxy-15β-hydroxymethylbeyeran-19-oic acid 4 and its ethyl ester 5 were synthesized in good yield with a facile method that has never been reported. The mechanism of this reaction was discussed and the mono-hydroxymethylation of carbonyl compound with two α-hydrogens via Tollens＇ reaction was firstly achieved. Compounds 2-5 were tested for activity of inhibition against glycosidases, among which 5 displays good inhibition of β-glucosidase and α-mannase, respectively.
文摘Two new compounds were isolated from the 60% ethanol extract of the dried rhizome of Ardisia gigantifolia Stapf. The structures were elucidated on the basis of spectroscopic methods as （＋）-5-（1,2-dihydroxypentyl）-benzene- 1,3-diol and （-）-5-（1,2- dihydroxypentyl）benzene- 1,3-diol.
文摘A new alkaloid, named 6-（2＇,3＇-dihydroxy-4＇-hydroxymethyl-tetrahydro-furan-1＇-yl）cyclopentadiene[c]pyrrole-1,3-diol, was isolated from the seeds of Castanea mollissima Blume. The structure was elucidated based on spectroscopic evidence including 2D NMR techniques.
