Studies On Synthesis Of A Nature Furan Lignans

Lignans belong to Phenylpropanoids,widely distributed in nature and have good pharmacological activity.Lignans are found in many medicinal plants,the structure of this kind of compound are changeable,include a simple small molecule lignans,but also have a very complex structure of macromolecular derivatives.Generally,lignans contain multiple chiral centers and a variety of functional groups.In this paper,we focus on the total synthesis of a nature furan lignans including the following three parts:Part one is the summery,we introduced the current study status of lignans including the definition,classification,extraction,separation,physicochemical properties,biological activities and the research progress in synthesis of various structural types.We summarized related lignans in recent years,also including the furan lignans on total synthesis conditions,in the end,we proposed the source of this topic according to the current research status of furan lignan compounds.The second part is the experiment,introduced the total synthesis process of the target compound in detail.We used 3,4,5-trimethoxy benzaldehyde as raw materials,by wittig greaction,preparation of free radical cyclization with trivalent acetic acid,final generation lactone.Then,the lactone reacts with 3,4,5-Trimethyl benzyl bromide under LDA,finally generation bromo product.Then,generate intermediate product furan lignans by reduction of lithium tetrahydrate and dehydration.In the end the mid product reacts with 2-methyl-2-butenoic acid esterification reaction to produce the final target compounds.The third part is the discussion.We discuss the reaction mechanism of important target compounds in the synthesis process,including the best ratio of raw materials and reaction mechanism,such as the trivalent manganese application,trivalent manganese catalytic reaction,the reduction reaction and,last we also discuss the other factors that affecting the reaction.