A new approach to alkaloid-like systems: synthesis and crystal structure of 1-(2-acetyl-11-meth­oxy-5,6-di­hydro­[1,3]dioxolo[4,5-g]pyrrolo­[2,1-a]isoquinolin-1-yl)propan-2-one

The title compound, C(19)H(19)NO(5), (I), is the product of a domino reaction between cotarnine chloride and acetyl­acetylene catalysed by copper(I) iodide. The mol­ecule of (I) comprises a fused tetra­cyclic system containing two terminal five-membered rings (pyrrole and 1,3-dioxole) and two central six-membered rings (di­hydro­pyridine and benzene). The five-membered 1,3-dioxole ring has an envelope conformation and the central six-membered di­hydro­pyridine ring adopts a twist-boat conformation. The acyl substituent is almost coplanar with the pyrrole ring, whereas the meth­oxy substituent is twisted by 27.93 (16)° relative to the benzene ring. The 2-oxopropan-1-yl substituent is roughly perpendicular to the pyrrole ring. In the crystal, mol­ecules are stacked along the a-axis direction; the stacks are linked by weak C—H⋯O hydrogen bonds into puckered layers lying parallel to (001).