Efficient Synthesis of Dihydrofuroquinolinones and Furoquinolinones by Silver(I)/Celite Promoted Oxidative Cycloaddition

A new synthesis of dihydrofuroquinolinones and furoquinolinones is achieved from 4-hydroxy-2-quinolones and a variety of olefins in the presence of Ag2CO3/Celite in moderate yields. The new method has been applied to the synthesis of the pseudoisodictamnine.