A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscop...A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscopie analysis and comparison with related compounds.展开更多
Although tea is grown in agro-ecological regions widely varying in environmental factors affecting yield and quality, planters usually import genetic materials across the different growing regions assuming genotypes w...Although tea is grown in agro-ecological regions widely varying in environmental factors affecting yield and quality, planters usually import genetic materials across the different growing regions assuming genotypes with good quality attributes in one location maintain their status in all regions. However, tea quality has not been replicated in new production regions. Black tea quality is influenced by the green leaf quality precursors including caffeine, total polyphenols and individual flavan-3-ols which are precursors of theaflavins and thearubigins, key plain black tea quality parameters. Factors influencing levels of the precursors compounds have not been quantified for popular Kenyan tea cultivars. The influence of geographical production location and seasons on levels and ratios of the quality precursors for 10 black tea popular clones grown in three locations in Kenya under uniform agronomic inputs were monitored. Caffeine varied significantly （P _〈 0.05） with clones and location but not with season. The flavan-3-ols and their ratios all varied （P 〈 0.05） with clones and site but not with season, with significant interactions （P 〈 0.05） between locations and clones, and locations and seasons. These results explain the observed variations in plain black tea quality due to clones and location of production. Thus, farmers in different locations are unlikely to produce black tea of same quality. It is therefore necessary to evaluate new tea genotypes in intended growing areas to establish cultivars suitable for producing high quality plain black teas in the locations. Seasonal variations in plain black tea in Kenya are unlikely to vary significantly due to flavan-3-ols.展开更多
Excess molar volumes (V^E_m) of binary mixtures of2-methyl-3-buten-3-ol [CH_3C(OH)(CH_3)CHCG_2] with four 1-alcohols:methanol, ethanol, 1-propanol and l-butanol at 298.15 K andatmospheric pressure are derived from den...Excess molar volumes (V^E_m) of binary mixtures of2-methyl-3-buten-3-ol [CH_3C(OH)(CH_3)CHCG_2] with four 1-alcohols:methanol, ethanol, 1-propanol and l-butanol at 298.15 K andatmospheric pressure are derived from density measurements with avibrating-tube densimeter. All the excess volumes are negative in thesystems over the entire composition range. The results are correlatedwith the Redlich-Kister equation. The effects of chain length ofl-alcohols on V^E_m are discussed. The apparent molar volumes of2-methyl-3-ol and l-alcohols are calculated respectively.展开更多
Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen recepto...Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen receptor-dependent breast cancer T47D cells.Methods:The proliferation effect of FPC were conducted on T47D cells in vitro by MTT test.T47D cells were treated with FPC alone(0.01-200μmol/L)or in combination with TAM 20 nmol/L.Furthermore,the expression of ERαor c-Myc were also determined by immunohistochemistry.Results:The results indicated that administration of an anti-estrogen TAM showed growth inhibitory effect on T47D cells,wheraes co-administered with low concentration(less than 1μmol/L)of FPC attenuated to promote cell proliferation.In contrast,the combination of TAM with higher doses(more than 20μmol/L)of FPC showed growth inhibitory.This result was supported by immunocytochemistry studies that the administration of 20 nmol/L TAM down-regulated ER-αand c-Myc,but the combination of 20 nmol/L TAM and 1μmol/L FPC robustly up-regulated expression of ER-α.Thus,the reduced growth inhibition of TAM 20 nmol/L by FPC 1μmol/L on T47D cells may act via the modulation of ER-α.Conclusions:The findings indicate and suggest that FPC had estrogenic activity at low concentrations and anti-estrogenic effect that are likely to be regulated by c-Myc and estrogen receptors.We also confirm that low concentration of FPC attenuated the growth-inhibitory effects of TAM on mammary tumor prevention.Therefore,the present study suggests that caution is warranted regarding the consumption of dietary FPC by breast cancer patients while on TMA therapy.展开更多
acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol（Ⅰ） was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one （Ⅱ） with overall yield of 52.7%. Thus, interaction of ethylene...acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol（Ⅰ） was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one （Ⅱ） with overall yield of 52.7%. Thus, interaction of ethylene glycol and material （Ⅱ） gave 3β-acetoxy- 17,17-ethylendioxy-15β,16β-methylene-5-androsten （Ⅲ） which was subsequently oxidated and stereoselectively reduced to produce compound（Ⅰ）. The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5H5N （1∶1, mole fraction）>CrO3-C5H5N（1∶2）>（C5H5NH）2Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 ℃, and n （Ⅲ）/ n （CrO3-C5H5N（1∶2））=1∶20. The yield of the -7β alcohol order with Li[Al（OC（CH3）3）3H] （e.g.78.6%） is more than that with NaBH4 （e.g.14.5%） in terms of the reductive （agent） and the reduction rate decreases in the course of reaction. The compound （Ⅰ） is characterized by IR and MS.展开更多
研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac i...研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。展开更多
A novel phenylpropanoid-substituted catechin glycoside glabraoside A 1 and a new dihydrochalcone 3＇-（7＂-allylphenyl）-2＇,4＇,4＂-trihydroxy-6＇-methoxydihydrochalcone 2 were isolated from the herbs of Sarcandra gl...A novel phenylpropanoid-substituted catechin glycoside glabraoside A 1 and a new dihydrochalcone 3＇-（7＂-allylphenyl）-2＇,4＇,4＂-trihydroxy-6＇-methoxydihydrochalcone 2 were isolated from the herbs of Sarcandra glabra. Their structures were elucidated on the basis of spectroscopic analyses and chiroptical methods.展开更多
The synthesis and properties of (Z)-1-(triphenylstannyl)-3-phenyl-1-buten-3-ol (1) are described. Compound 1 crystallizes from alcohol in the monoclinic space group P21/c with unit-cell dimensions a=9.296(2), 6=14.081...The synthesis and properties of (Z)-1-(triphenylstannyl)-3-phenyl-1-buten-3-ol (1) are described. Compound 1 crystallizes from alcohol in the monoclinic space group P21/c with unit-cell dimensions a=9.296(2), 6=14.081(3), c=18.390(5) A,B=97.70(2), V=2385.5(1) A3, Z=4, F(000)=1008, Dc=1.38 g.cm-3,u=10.88 cm-1, final R=0.0359 for 3079 observed reflection [I > 3(I)]. The X-ray diffraction analysis of this compound shows the presence of an intramolecular coordination to the tin atom giving rise to a five-membered ring in which the metal exhibits a distroted trignoal bipyramidal geometry; as a consequence, a phenyl group, probably the apical one, is cleaved more easily by bromine than the vinyl substituent.展开更多
2-[3,5-Di-O-β-D-glucosyl-4-(3-methylbut-2-enyl)phenyl]benzofuran-6-ol,a new prenylated arylbenzofuran derivative was isolated from Morus alba L.Its structure was elucidated by various spectroscopic methods including ...2-[3,5-Di-O-β-D-glucosyl-4-(3-methylbut-2-enyl)phenyl]benzofuran-6-ol,a new prenylated arylbenzofuran derivative was isolated from Morus alba L.Its structure was elucidated by various spectroscopic methods including MS,~1H NMR,^(13)C NMR,DEPT,~1H-~1HCOSY,HMQC and HMBC.展开更多
Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to ...Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to dietary intake.We systematically searched published literature written in English via PubMed by searching for terms related to stomach and colorectal cancer risk and dietary flavonoids up to June 30,2012.Twenty-three studies out of 209 identified articles were finally selected for the analysis.Log point effect estimates and the corresponding standard errors were calculated using covariate-adjusted point effect estimates and 95%CIs from the selected studies.Total dietary flavonoid intake was not associated with a reduced risk of colorectal or stomach cancer [odds ratio(OR)(95%CI) = 1.00(0.90-1.11) and 1.07(0.70-1.61),respectively].Among flavonoid subclasses,the intake of flavonols,flavan-3-ols,anthocyanidins,and proanthocyanidins showed a significant inverse association with colorectal cancer risk [OR(95%CI) = 0.71(0.63-0.81),0.88(0.79-0.97),0.68(0.56-0.82),and 0.72(0.61-0.85),respectively].A significant association was found only between flavonols and stomach cancer risk based on a limited number of selected studies [OR(95%CI) = 0.68(0.46-0.99)].In the summary estimates from casecontrol studies,all flavonoid subclasses except flavones and flavanones were inversely associated with colorectal cancer risk,whereas neither total flavonoids nor any subclasses of flavonoids were associated with colorectal cancer risk in the summary estimates based on the cohort studies.The significant association between flavonoid subclasses and cancer risk might be closely related to bias derived from the case-control design.There was no clear evidence that dietary flavonoids are associated with reduced risk of stomach and colorectal cancer.展开更多
We compared two different strategies to increase the catches oflps typographus （L.）, particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone ble...We compared two different strategies to increase the catches oflps typographus （L.）, particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone blends, targeting males and females respectively, in closely-spaced traps forming a barrier around forest stands. The second strategy, the single trap approach, used widely-spaced traps that were all baited with the same lure and intended to trap the highest possible numbers of males without compromising trapping of females. In the blend used for the barrier traps targeting primarily males, with a lower percentage of （4S）-cis-verbenol （cV）, the （-）-α-pinene was replaced step wise with （＋）-limonene at rates of 0%, 1%, 10%, 35%, 60% and 90%. This replacement had no significant effect on the numbers of responding 1. typographus males, but there was a slight effect on the percentage of males caught. In the attractant blend for the barrier traps targeting females, with a higher percentage of cV, the 2-methyl-3-buten-2-ol （MB） was replaced with 1-methoxy-2-propanol （MP） in a similar fashion as for the male-specific blends. The replacement did not significantly affect the catch of females. Thus, it is pos- sible to use the MP in the blend with cV and ipsdienol without significant change in catch efficacy. In the blends for single traps, the （-）-α- pinene was replaced with （＋）-limonene and MB with MP. The replacement of （-）-α-pinene had only a slight effect on the percentage of males, but the results suggest that replacing MB with MP in the blend will not significantly reduce trapping efficacy.展开更多
An inexpensive synthesis of 6-ethynylbipyridine has been accomplished using Sonogashira coupling of 2-bromo-6-iodopyridine with 2-methyl-3-butyn-2-ol. Subsequent Stille coupling with 2-(trimethylstannanyl) pyridine an...An inexpensive synthesis of 6-ethynylbipyridine has been accomplished using Sonogashira coupling of 2-bromo-6-iodopyridine with 2-methyl-3-butyn-2-ol. Subsequent Stille coupling with 2-(trimethylstannanyl) pyridine and hydrolysis provided the target compound in an overall high yield.展开更多
文摘A new flavan-3-ol glucoside, (-)-afzelechin-7-O-β-D-glucopyranoside (1), has been isolated from the stem of Daphniphyllum oldhami. The structure of the new compound was elucidated on the basis of detailed spectroscopie analysis and comparison with related compounds.
文摘Although tea is grown in agro-ecological regions widely varying in environmental factors affecting yield and quality, planters usually import genetic materials across the different growing regions assuming genotypes with good quality attributes in one location maintain their status in all regions. However, tea quality has not been replicated in new production regions. Black tea quality is influenced by the green leaf quality precursors including caffeine, total polyphenols and individual flavan-3-ols which are precursors of theaflavins and thearubigins, key plain black tea quality parameters. Factors influencing levels of the precursors compounds have not been quantified for popular Kenyan tea cultivars. The influence of geographical production location and seasons on levels and ratios of the quality precursors for 10 black tea popular clones grown in three locations in Kenya under uniform agronomic inputs were monitored. Caffeine varied significantly （P _〈 0.05） with clones and location but not with season. The flavan-3-ols and their ratios all varied （P 〈 0.05） with clones and site but not with season, with significant interactions （P 〈 0.05） between locations and clones, and locations and seasons. These results explain the observed variations in plain black tea quality due to clones and location of production. Thus, farmers in different locations are unlikely to produce black tea of same quality. It is therefore necessary to evaluate new tea genotypes in intended growing areas to establish cultivars suitable for producing high quality plain black teas in the locations. Seasonal variations in plain black tea in Kenya are unlikely to vary significantly due to flavan-3-ols.
基金Supported by the National Natural Science Foundation of China (No. 29976035).
文摘Excess molar volumes (V^E_m) of binary mixtures of2-methyl-3-buten-3-ol [CH_3C(OH)(CH_3)CHCG_2] with four 1-alcohols:methanol, ethanol, 1-propanol and l-butanol at 298.15 K andatmospheric pressure are derived from density measurements with avibrating-tube densimeter. All the excess volumes are negative in thesystems over the entire composition range. The results are correlatedwith the Redlich-Kister equation. The effects of chain length ofl-alcohols on V^E_m are discussed. The apparent molar volumes of2-methyl-3-ol and l-alcohols are calculated respectively.
基金Supported in part by Hibah Competition Grant Research of Faculty of PharmacyGadjah Mada University(Grant No.UGM/FA/851.d/M/05/01)
文摘Objective:To investigate the estrogenic effect of(8,9)-furanyl-pterocarpan-3-ol(FPC)on growth of human breast cancer T47D cells and the interactions between the FPC and tamoxifen(TAM),on the growth of estrogen receptor-dependent breast cancer T47D cells.Methods:The proliferation effect of FPC were conducted on T47D cells in vitro by MTT test.T47D cells were treated with FPC alone(0.01-200μmol/L)or in combination with TAM 20 nmol/L.Furthermore,the expression of ERαor c-Myc were also determined by immunohistochemistry.Results:The results indicated that administration of an anti-estrogen TAM showed growth inhibitory effect on T47D cells,wheraes co-administered with low concentration(less than 1μmol/L)of FPC attenuated to promote cell proliferation.In contrast,the combination of TAM with higher doses(more than 20μmol/L)of FPC showed growth inhibitory.This result was supported by immunocytochemistry studies that the administration of 20 nmol/L TAM down-regulated ER-αand c-Myc,but the combination of 20 nmol/L TAM and 1μmol/L FPC robustly up-regulated expression of ER-α.Thus,the reduced growth inhibition of TAM 20 nmol/L by FPC 1μmol/L on T47D cells may act via the modulation of ER-α.Conclusions:The findings indicate and suggest that FPC had estrogenic activity at low concentrations and anti-estrogenic effect that are likely to be regulated by c-Myc and estrogen receptors.We also confirm that low concentration of FPC attenuated the growth-inhibitory effects of TAM on mammary tumor prevention.Therefore,the present study suggests that caution is warranted regarding the consumption of dietary FPC by breast cancer patients while on TMA therapy.
文摘acetoxy-17,17-ethylendioxy-15β,16β-methylene-5-androsten-7β-ol（Ⅰ） was prepared by 3 steps from 3β-acetoxy-15β,16β-methylene-5-androsten-17-one （Ⅱ） with overall yield of 52.7%. Thus, interaction of ethylene glycol and material （Ⅱ） gave 3β-acetoxy- 17,17-ethylendioxy-15β,16β-methylene-5-androsten （Ⅲ） which was subsequently oxidated and stereoselectively reduced to produce compound（Ⅰ）. The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5H5N （1∶1, mole fraction）>CrO3-C5H5N（1∶2）>（C5H5NH）2Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 ℃, and n （Ⅲ）/ n （CrO3-C5H5N（1∶2））=1∶20. The yield of the -7β alcohol order with Li[Al（OC（CH3）3）3H] （e.g.78.6%） is more than that with NaBH4 （e.g.14.5%） in terms of the reductive （agent） and the reduction rate decreases in the course of reaction. The compound （Ⅰ） is characterized by IR and MS.
文摘研究了民间草药甜草O ldenlandia cantonensisHow的化学成分。从乙醇提取物的乙酸乙酯洗脱部分得到新的五环三萜urs-12-en-29-αoic ac id-3β-ol。该化合物结构通过NMR、IR、MS等波谱数据综合解析确定。研究了urs-12-en-29-αoic ac id-3β-ol对重组人DNA拓扑异构酶Ⅰ、肝癌细胞BEL-7402和胃腺癌细胞MCG-803的抑制作用,效果显著,IC50值分别为12.0×10-6、6.5×10-6、8.0×10-6g/mL。由V(石油醚)∶V(乙酸乙酯)=20∶1洗脱得到的低极性成分进行了气相色谱-质谱分析,共鉴定60个化合物,其中长链脂肪族化合物,如烷烃、饱和及不饱和羧酸(酯)含量较丰富,占36.16%,萜类和甾体类化合物分别占6.42%和9.28%。
基金the National Natural Science Foundation of China （No. 20432030） for financial support.
文摘A novel phenylpropanoid-substituted catechin glycoside glabraoside A 1 and a new dihydrochalcone 3＇-（7＂-allylphenyl）-2＇,4＇,4＂-trihydroxy-6＇-methoxydihydrochalcone 2 were isolated from the herbs of Sarcandra glabra. Their structures were elucidated on the basis of spectroscopic analyses and chiroptical methods.
基金Project supported by the National Natural Sciences Foundation of China.
文摘The synthesis and properties of (Z)-1-(triphenylstannyl)-3-phenyl-1-buten-3-ol (1) are described. Compound 1 crystallizes from alcohol in the monoclinic space group P21/c with unit-cell dimensions a=9.296(2), 6=14.081(3), c=18.390(5) A,B=97.70(2), V=2385.5(1) A3, Z=4, F(000)=1008, Dc=1.38 g.cm-3,u=10.88 cm-1, final R=0.0359 for 3079 observed reflection [I > 3(I)]. The X-ray diffraction analysis of this compound shows the presence of an intramolecular coordination to the tin atom giving rise to a five-membered ring in which the metal exhibits a distroted trignoal bipyramidal geometry; as a consequence, a phenyl group, probably the apical one, is cleaved more easily by bromine than the vinyl substituent.
基金supported by the Great Research Project of National Major New Drug Development(No. 2009ZX09102-110)
文摘2-[3,5-Di-O-β-D-glucosyl-4-(3-methylbut-2-enyl)phenyl]benzofuran-6-ol,a new prenylated arylbenzofuran derivative was isolated from Morus alba L.Its structure was elucidated by various spectroscopic methods including MS,~1H NMR,^(13)C NMR,DEPT,~1H-~1HCOSY,HMQC and HMBC.
文摘Stomach and colorectal cancers are common cancers and leading causes of cancer deaths.Because the alimentary tract can interact directly with dietary components,stomach and colorectal cancer may be closely related to dietary intake.We systematically searched published literature written in English via PubMed by searching for terms related to stomach and colorectal cancer risk and dietary flavonoids up to June 30,2012.Twenty-three studies out of 209 identified articles were finally selected for the analysis.Log point effect estimates and the corresponding standard errors were calculated using covariate-adjusted point effect estimates and 95%CIs from the selected studies.Total dietary flavonoid intake was not associated with a reduced risk of colorectal or stomach cancer [odds ratio(OR)(95%CI) = 1.00(0.90-1.11) and 1.07(0.70-1.61),respectively].Among flavonoid subclasses,the intake of flavonols,flavan-3-ols,anthocyanidins,and proanthocyanidins showed a significant inverse association with colorectal cancer risk [OR(95%CI) = 0.71(0.63-0.81),0.88(0.79-0.97),0.68(0.56-0.82),and 0.72(0.61-0.85),respectively].A significant association was found only between flavonols and stomach cancer risk based on a limited number of selected studies [OR(95%CI) = 0.68(0.46-0.99)].In the summary estimates from casecontrol studies,all flavonoid subclasses except flavones and flavanones were inversely associated with colorectal cancer risk,whereas neither total flavonoids nor any subclasses of flavonoids were associated with colorectal cancer risk in the summary estimates based on the cohort studies.The significant association between flavonoid subclasses and cancer risk might be closely related to bias derived from the case-control design.There was no clear evidence that dietary flavonoids are associated with reduced risk of stomach and colorectal cancer.
基金supported by Slovak Research and Development Agency (APVV-51-P06005 and APVV-27-P05205)the Scientific Grant Agency of the Ministry of Education of the Slovak Republic and the Slovak Academy of Sciences (2/6153/26)
文摘We compared two different strategies to increase the catches oflps typographus （L.）, particularly males, in pheromone-baited traps. The first of these strategies, the barrier approach, used alternating pheromone blends, targeting males and females respectively, in closely-spaced traps forming a barrier around forest stands. The second strategy, the single trap approach, used widely-spaced traps that were all baited with the same lure and intended to trap the highest possible numbers of males without compromising trapping of females. In the blend used for the barrier traps targeting primarily males, with a lower percentage of （4S）-cis-verbenol （cV）, the （-）-α-pinene was replaced step wise with （＋）-limonene at rates of 0%, 1%, 10%, 35%, 60% and 90%. This replacement had no significant effect on the numbers of responding 1. typographus males, but there was a slight effect on the percentage of males caught. In the attractant blend for the barrier traps targeting females, with a higher percentage of cV, the 2-methyl-3-buten-2-ol （MB） was replaced with 1-methoxy-2-propanol （MP） in a similar fashion as for the male-specific blends. The replacement did not significantly affect the catch of females. Thus, it is pos- sible to use the MP in the blend with cV and ipsdienol without significant change in catch efficacy. In the blends for single traps, the （-）-α- pinene was replaced with （＋）-limonene and MB with MP. The replacement of （-）-α-pinene had only a slight effect on the percentage of males, but the results suggest that replacing MB with MP in the blend will not significantly reduce trapping efficacy.
文摘An inexpensive synthesis of 6-ethynylbipyridine has been accomplished using Sonogashira coupling of 2-bromo-6-iodopyridine with 2-methyl-3-butyn-2-ol. Subsequent Stille coupling with 2-(trimethylstannanyl) pyridine and hydrolysis provided the target compound in an overall high yield.
