7-oxo-2,3,4,5-tetrahydro-1H,7H-[1,3]dioxolo[4,5-j]pyrrolo[3,2,1-de]phenanthridine-3a-carboxylic acid methyl ester

2,7-dioxo-2,3,4,5-tetrahydro-1H,7H-[1,3]dioxolo[4,5-j]pyrrolo[3,2,1-de]phenanthridine-3a-carboxylic acid methyl ester

methyl 7-oxo-4,5-dihydro-1H,3H-spiro[[1,3]dioxolo[4,5-j]pyrrolo[3,2,1-de]phenanthridine-2,2'-[1,3]dithiolane]-3a(7H)-carboxylate