Study On The Synthesis Of Polysubstituted 1,5-pentanediones Based On M-S Rearrangement

In this thesis,the self-addition reaction of aryl propargyl alcohol after Meyer-Schuster rearrangement reaction and the tandem reaction of aryl propargyl alcohol withα,βunsaturated ketones were studied,the results show that aryl-substituted propargyl alcohols can be widely used as substrates for Meyer-Schuster rearrangements.This provides a convenient method for the synthesis of multi-substituted 1,5-pentanedione.The self-addition reaction of aryl propargyl alcohol after Meyer-Schuster rearrangement catalyzed by Lewis acid was studied.In the study,the catalyst was screened first,then the solvent was screened.The results showed that the optimal reaction conditions were:Catalyst was Bi（OTF）₃,The Solvent was DCE,and the reaction was carried out under reflux condition.The method has the advantages of wide applicability of substrates,high yield,100%atomic utilization and simple operation.In the first part,we try to replace the phenylpropargyl alcohol Meyer-Schuster rearrangement intermediate-phenyl-vinyl ketone withα,β-unsaturated ketones which are more electrophilic,5-pentanedione method.The effects of different Lewis acid catalysts and different solvents on the reaction were studied,and the optimum reaction condition was determined as 10%Bi（OTF）₃Refluxing in DCE.Then the universality ofα,βunsaturated ketones and propargyl alcohols was studied.Then aryl diketone malonitrile compounds were synthesized by one-pot reaction of methenone and malononitrile promoted by alkali.The experimental results show that these transformations can be used for amplification reaction.The synthesis method has the advantages of high yield,simple experimental operation and 100%atomic utilization.