Study On The Ring-opening Reaction Of Cyclopropane And Its Derivatives

Unsaturated aliphatic carboxylic acid ester is a kind of very important structural skeleton,it has enormous application value in the fields of medicine,pesticides,dyes,functional materials and spices.What's more,ethyl?E?-4-phenylbut-3-enoate derivatives can be used in synthesizing the pharmaceutical compounds,in hence to the significance of the ethyl?E?-4-phenylbut-3-enoate derivatives,how to efficiently synthesize ethyl?E?-4-phenylbut-3-enoate and its derivatives have been caused widespread concern.Owing to the good performance during the catalytic process,Lewis acid promote and its co-catalyzed reaction have been studied by many researchers.And the mechanism of the Lewis acid and transition metal co-catalyzed reaction can achieve good results in different reaction types.On the other hand,cyclopropane with donor-acceptor group can activated the carbon-carbon bond relay on the special structure,and then undergo a series of reactions after being catalyzed by Lewis acid.In this paper,a new type of the ring-opening reaction of cyclopropane with donor-acceptor group and other derivatives is described.That is,diethyl 2-phenylcyclopropane-1,1-dicarboxylate and its derivatives undergo molecular isomerization and elimination reaction under the catalysis of aluminum chloride,ethyl?E?-4-phenylbut-3-enoate were obtained in moderated yields.The results showed that this reaction has good functional group tolerance.Product and reactant 1i,2i etc.were unknown,and their structures were confirmed by ¹H NMR,¹³C NMR,IR and HRMS.