A dearomatization–rearomatization strategy for construction of 4H-quinolizin-4-ones via C–H bond functionalization of pyridines

Herein, the synthesis of 4 H -quinolizin-4-ones from N -(2-methoxy-2-oxoethyl) pyridinium salts and alkenes through dearomative cycloaddition and rearomative ring expansion has been developed.