In this study,three sorts of polyols were successfully synthesized from castor oil using a Dean-Stark quick,eco-friendly and high-efficiency method.For this purpose,castor oil was epoxidized in the presence of two typ...In this study,three sorts of polyols were successfully synthesized from castor oil using a Dean-Stark quick,eco-friendly and high-efficiency method.For this purpose,castor oil was epoxidized in the presence of two types of catalysts includingγ-alumina and formic acid,named as ECOAl and ECOF,respectively.Epoxidized castor oils were then characterized by use of hydrogen nuclear magnetic resonance(H-NMR)and oxirane oxygen content analysis.The relative percentages of conversion double bond to oxirane were obtained 96% and 74% for ECOAl and ECOF,respectively.Ring opening reaction of ECOAl was performed by two types of saponified castor oil as well as castor oil in a system equipped with Dean–Stark apparatus.The synthesized polyols were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR),gel permeation chromatography(GPC),differential scanning calorimetry(DSC),viscometer and OH number evaluation.The material obtained in this research is a candidate to be intended in synthesis of polyurethane for coating applications.展开更多
Title compounds 2′,2′-dimethylcholesta-2,4-dien[3,2-b]-pyran-4′-one （3）, 2′,2′-dimethyl-3β-substituted cholesta-4,6-dien[7,6- b]-pyran-4′-one （6a,b） and （6c） were prepared by the cyclization of 2-acetylch...Title compounds 2′,2′-dimethylcholesta-2,4-dien[3,2-b]-pyran-4′-one （3）, 2′,2′-dimethyl-3β-substituted cholesta-4,6-dien[7,6- b]-pyran-4′-one （6a,b） and （6c） were prepared by the cyclization of 2-acetylcholesta-2,4-dien-3-ol （2）, 6-acetyl-3β-substituted- cholesta-4,6-dien-7-ol （Sa,b） and （5c） respectively, with pyrrolidine, dry benzene and dry acetone using Dean Stark separator through conventional heating. Furthermore, compounds were also found to be active against Mycobacterium tuberculosis.展开更多
文摘In this study,three sorts of polyols were successfully synthesized from castor oil using a Dean-Stark quick,eco-friendly and high-efficiency method.For this purpose,castor oil was epoxidized in the presence of two types of catalysts includingγ-alumina and formic acid,named as ECOAl and ECOF,respectively.Epoxidized castor oils were then characterized by use of hydrogen nuclear magnetic resonance(H-NMR)and oxirane oxygen content analysis.The relative percentages of conversion double bond to oxirane were obtained 96% and 74% for ECOAl and ECOF,respectively.Ring opening reaction of ECOAl was performed by two types of saponified castor oil as well as castor oil in a system equipped with Dean–Stark apparatus.The synthesized polyols were characterized by attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR),gel permeation chromatography(GPC),differential scanning calorimetry(DSC),viscometer and OH number evaluation.The material obtained in this research is a candidate to be intended in synthesis of polyurethane for coating applications.
文摘Title compounds 2′,2′-dimethylcholesta-2,4-dien[3,2-b]-pyran-4′-one （3）, 2′,2′-dimethyl-3β-substituted cholesta-4,6-dien[7,6- b]-pyran-4′-one （6a,b） and （6c） were prepared by the cyclization of 2-acetylcholesta-2,4-dien-3-ol （2）, 6-acetyl-3β-substituted- cholesta-4,6-dien-7-ol （Sa,b） and （5c） respectively, with pyrrolidine, dry benzene and dry acetone using Dean Stark separator through conventional heating. Furthermore, compounds were also found to be active against Mycobacterium tuberculosis.
