(1S*,4′S*,5R*)-1-Isopropyl-5-methoxy-2′,3-dimethyl-4,6-dioxa-2-azaspiro[bicyclo[3.2.0]hept-2-ene-7,4′-isoquinoline]-1′,3′(2′H,4′H)-dione

In the isoquinoline ring system of the title molecule, C18H20N2O5, the N-heterocyclic ring is in a half-boat conformation. The dioxa-2-azaspiro ring is essentially planar, with a maximum deviation of 0.029 (1) Å, and makes a dihedral angle of 30.63 (5)° with the benzene ring. The molecular structure is stabilized by a weak intramolecular C—H...O hydrogen bond, which generates a S(6) ring motif. In the crystal, molecules are linked via weak intermolecular C—H...O hydrogen bonds into a three-dimensional supramolecular network. Additional stabilization is provided by π–π stacking interactions between symmetry-related benzene rings with a centroid–centroid distance of 3.6507 (5) Å.