Study On The Synthesis Of A Class Of Furan Lignans

Many lignans widely distribute in nature,most of lignans have a variety of biological activities,which are the active ingredient of many traditional Chinese medicines.At present,the synthesis of lignans has been paid more and more attention by chemists,more reports about the synthesis of lignans have been reported.In this paper,the definition,classification,separation and purification,physical and chemical properties,synthesis and research status of lignans were summarized,meanwhile,the total synthesis route and the optimum reaction conditions of furan lignans is studied,the main researches are as follows:Part 1,in this paper,the definition,nomenclature,separation and purification,classification,biological activity,physical and chemical properties and synthetic study of lignans were introduced,analysising the synthetic routes and methods of lignans,in this paper,we put forward the synthetic route and method of furan lignans.Part 2,The best synthetic routes of two kinds of furan lignins are introduced,full details of the total synthesis of the compound 2-methyl-(2E)-butenoic acid,[(2S,3R,4R)-2-(3,4-dimethoxyphenyl)-4-[(3,4-dimethoxyphenyl)methyl]tetrahydro-3-furanyl]methyl ester,starting from veratraldehyde,were developed.The convergent synthesis was based on the Stobbe reaction,esterification reaction and Aldol reaction as the key steps to give the skeleton of lignan,though two steps of reduction reaction and esterification reaction,the final product was obtained.We used cheaper syringaldehyde as raw material to synthesize the compound 3-(4-hydroxy-3-methoxyphenyl)-(2E)-Propenoic acid,[(2S,3R,4R)-2-(4-hydroxy-3,5-dimethoxyphenyl)-4-[(4-hydroxy-3,5-dimethoxyphenyl)methyl]-3-tetrahydrofuranyl]methyl ester,the convergent synthesis was based on benzyl protection reaction,the Stobbe reaction,esterification reaction and Aldol reaction as the key steps to give the skeleton of lignan,though reduction reaction,dehydration reaction,esterification reaction,deprotection reaction,the final product was obtainedPart 3,the reaction of each step in the experiment is discussed,the optimum reaction conditions were determined by comparing the factors such as catalyst,solvent,reaction time,reaction temperature,feed ratio and so on,thus we determine the best reaction route of whole experiment.