DABCO and Bu3P catalyzed [4 + 2] and [3 + 2] cycloadditions of 3-acyl-2H-chromen-ones and ethyl 2,3-butadienoate
作者:Ying Wang、Zhi-Hua Yu、Hu-Fei Zheng、De-Qing Shi
DOI:10.1039/c2ob26300a
日期:——
DABCO-catalyzed [4 + 2] and Bu3P-catalyzed [3 + 2] cycloadditions between 3-acyl-2H-chromen-ones and ethyl 2,3-butadienoate were developed for the synthesis of dihydropyran-fused and cyclopenten-fused chromen-2-ones with high regio- and stereo-selectivities, respectively. The synthetic procedures have the advantages of mild reaction conditions, convenient handling and good atom economy as well as a wide substrate scope, which make this method useful for the synthesis of potentially biologically active dihydropyran-fused and cyclopenten-fused chromen-2-ones derivatives. Possible reaction mechanisms have also been proposed on the basis of previous literature and our investigation.