Synthesis Of Aurones And Flavones By Intramolecular Cyclizaiion Of O-Alkynovlphenols

In this thesis, the intramolecular cyclization of o-alkynoylphenols was studied and a series of aurones and flavones were synthesized. The thesis consists of the following two parts:Firstly, we studied the synthesis of aurones and flavones by intramolecular cyclization reaction of o-alkynoylphenols.n-Bu3P-catalyzed intramolecular cyclization of o-alkynoylphenols was investigated and the results show that the addition reaction between phenolic hydroxyl of o-alkynoylphenols and intramolecular carbon-carbon triple bond proceeded smoothly.13aurones were obtained while the groups connected to the carbon-carbon triple bond were aryl and5flavones were obtained while the groups connected to the carbon-carbon triple bond were alkyl. All products were characterized by1H NMR,13C NMR, IR and HRMS. The molecular structure of compound (Z)-2-(4-methylbenzylidene)-benzofuran-3(2H)-one (2b) was determined by X-ray diffraction analysis.Secondly, we studied the synthesis of3-iodoflavones by iodocyclization reaction of o-alkynoylphenols.133-iodoflavones were synthesized by one-pot iodocyclization reaction of o-alkynoylphenols and I2/NaHCOs. The reaction proceed in high regio selectivity. All products were characterized by1H NMR,13C NMR, IR and HRMS.The research results provided a new method to synthesize aurones or flavones. The method has the advantages of easily available starting materials and simple operation. The further transformation of these compounds was possible because of the existence of carbonyl and iodo functional groups.