A Study On The Cascade Reaction Of Alkyl 2-aroyl-1-chlorocyclopropanecarboxylates And Hydroxy Chalcones

Chalcone compounds,as important intermediates,are widely used in the field of organic synthesis,drug synthesis and materials synthesis.Tetrahydrocyclopropa[b]chromene compounds are considered as a class of biologically active molecules with potential application value,this kind of compounds can be synthesized by Michael receptor with olefins in cycloaddition.T herefore,building this kind of compounds effectively is becoming a meaningful research.Liter ature survey shows that the methods of synthesizing the compounds are so limited,mainly t hrough the construction of ternary-ring compounds indirectly.Inconsideration of building this c ompounds via base catalysis chalcone compound are rarely reported,in this thesis,we mainly carried out the study of Oxa-addition cascade reaction between containing donor-receptor 2-hy droxy chalcone compounds and reactive cyclopropene intermediate bearing two electron-withdr aw group,the detail studies are as follows:(1)We explored the reaction of salicylaldehyde with chalcone in the presence of base,an d a series of 2-hydroxy chalcone compounds were synthesized.In the presence of sodium hy droxide,eight 2-hydroxy chalcone compounds product were obtained with high yield(up to 88%)at room temperature when the reaction was conducted in ethanol and water based the al dol cascade reaction between them.(2)We studied the reaction of 2-acyl-1-chlorocyclopropanescarboxilic esters with 2-hydrox y chalcone in the presence of base,and a series of tetrahydrocyclopropa[b]chromene compoun ds were constructed with potential application value.The experiment dates shown that experim ental condition such as solvent and the structure of reactants had crucial influence on the exp erimental results.In the presence of cesium carbonate,the Oxa-addition cascade reaction betw eenthem obtained a series of tetrahydrocyclopropa[b]chromene compounds with high yield(up t o 91%)at room temperature when the reaction was conducted in DMF.The NOESY spectru m shown that the configuration of main product is trans-configuration.(3)Under expropriation above,scope of corresponding substrate was explored under the optimal conditions,it had good universality to the substrate.Furthermore,we also explored w hether the Lewis acid additive would have an effect on the diastereoselectivity of the product.The experiment dates shown that the ratio of trans-3aa was significantly reduced and the tra ns-3aa was inhibited,the diastereoselectivity of the product changed.We had proposed the cor responding reaction pathway.