2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were inve...2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were investigated.The results showed that the optimum conditions were as follows:6methyl5heptene2one:1,2Propandiol:catalyst:dehydrating agent is 1 mol:15mol∶12g∶200ml;reaction temperature was reflux temperature;reaction time was 25h.The yield was above 915% under the optimum conditions.The catalyst can be used repeatedly.展开更多
The authors synthesized two novel flavanones bearing iso-pentenyl side chain and evaluated their anti Staphylococcus aureus(S.aureus) activity.The target compounds 7a[2-5'-(l",2"-dimethylallyl)-2'-methoxy-4',...The authors synthesized two novel flavanones bearing iso-pentenyl side chain and evaluated their anti Staphylococcus aureus(S.aureus) activity.The target compounds 7a[2-5'-(l",2"-dimethylallyl)-2'-methoxy-4',5,7-tetrahydroxyflavanone] and 7b[2-5'-(l",2"-dimethylallyl)-3'-methoxy-4',5,7-tetrahydroxyflavanone] were synthesized respectively through total four steps starting from 2,4,6-trihydroxy acetophenone(3) and the corresponding iso-pentenyl substituted benzaldehyde(1),in which the 1,2-dimethyl-2-propenyl group had been introduced previously via abnormal Claisen rearrangement.The bioactivities of the two flavanones against S.aureus strains ATCC 25923,29213,and MRSA 252 were evaluated,showing the same minimum inhibitory concentration(MIC) value of 16 μg/mL.展开更多
文摘2,4Dimethyl2(4methyl3Pentenyl)1,3dioxolane were synthesized with the phosphotungstic acid supported on cationic exchange resin as a catalyst.Various factors that affect the condensation yield were investigated.The results showed that the optimum conditions were as follows:6methyl5heptene2one:1,2Propandiol:catalyst:dehydrating agent is 1 mol:15mol∶12g∶200ml;reaction temperature was reflux temperature;reaction time was 25h.The yield was above 915% under the optimum conditions.The catalyst can be used repeatedly.
文摘The authors synthesized two novel flavanones bearing iso-pentenyl side chain and evaluated their anti Staphylococcus aureus(S.aureus) activity.The target compounds 7a[2-5'-(l",2"-dimethylallyl)-2'-methoxy-4',5,7-tetrahydroxyflavanone] and 7b[2-5'-(l",2"-dimethylallyl)-3'-methoxy-4',5,7-tetrahydroxyflavanone] were synthesized respectively through total four steps starting from 2,4,6-trihydroxy acetophenone(3) and the corresponding iso-pentenyl substituted benzaldehyde(1),in which the 1,2-dimethyl-2-propenyl group had been introduced previously via abnormal Claisen rearrangement.The bioactivities of the two flavanones against S.aureus strains ATCC 25923,29213,and MRSA 252 were evaluated,showing the same minimum inhibitory concentration(MIC) value of 16 μg/mL.