(4'-Acet-yloxy-1,3,1'-trioxo-1,3,4,4a,4b,5,6,7,9,9a-deca-hydro-spiro-[indene-2,9'-pyrano[4,3-a]pyrrolizin]-3'-yl)methyl acetate.

In the title compound, C23H23NO8, the dihedral angle between the five- and six-membered rings of the indene-dione moiety is 3.09†(13)°. The mean plane of the five-membered ring (which has a flat envelope conformation with the spiro C atom as the flap) is inclined to the mean plane of the central five-membered ring of the pyrrolizine unit by 76.48†(12)°. This central ring has a twist conformation on the N-C(spiro) bond. The outer ring of the pyrrolizine unit has an envelope conformation with the N atom as the flap. The mean planes of these two fused rings are inclined to one another by 65.28†(15)°. The pyran ring has a screw-boat conformation and its mean plane makes a dihedral angle of 29.50†(11)° with the mean plane of the central five-membered ring of the pyrrolizine unit. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane.