Biology-oriented synthesis of benzopyrano[3,4-c]pyrrolidines.

Abstract A natural product inspired synthesis of 6,6,5-tricyclic compounds via a silver(I)-catalyzed formal 1,3-dipolar cycloaddition of coumarins with α-iminoesters was developed. The reaction proceeds in a stepwise reaction course under formation of the trans -substituted diastereomer with respect to the 1,3-dipole and shows a broad substrate scope.