Inverse electron-demand Diels–Alder chemistry in the synthesis of a regioselectively protected analogue of the staurosporine aglycone

Regioselective Weinreb amidation of the C1 ester of dimethyl pyridazino[4,5-b]indole-1,4-dicarboxylate followed by an intramolecular inverse electron-demand Diels–Alder reaction and palladium-catalyzed coupling produced regioselectively protected N6-methylindolo[2,3-a]pyrrolo[3,4-c]carbazole (N6-methylstaurosporinone).