Efficient One‐Pot Synthesis of Hydroxyflavanones by Cyclization andO‐Demethylation of Methoxychalcones

Abstract An efficient one‐pot method for the synthesis of hydroxyflavanones is described. Methoxychalcones are treated with 36% HBr to afford cyclization and regioselective O‐demethylation products (2a–i) while cyclization and complete O‐demethylation products (3a–e) are obtained in the presence of 45% HI. Keywords: Cyclization O‐demethylationhydrobromic acidhydroiodic acidhydroxyflavanonesmethoxychalcones Acknowledgments This work was supported by the Natural Science Foundation of Zhejiang Province of China (Project No. Y206340). We also gratefully thank the Experimental Center of School of Pharmaceutical Sciences in Zhejiang University, China.