(1S,1'S,2'R,4a'S,9a'S,9b'R)-1'-Acet­yloxy-2,4'-dioxo-2',4',4a',7',8',9',9a',9b'-octa­hydro-1'H,2H-spiro­[ace­naphthyl­ene-1,5'-pyrano[4,3-a]pyrrolizin]-2'-ylmethyl acetate

In the title compound C₂₆H₂₅NO₇, the mean plane through the lactone-substituted ring of the pyrrolizidine moiety forms dihedral angles of 78.46 (6) and 58.28 (8)° with the ace­naphthyl­ene moiety and the sugar based-lactone ring, respectively. The sum of the angles at the the N atom of the pyrrolizidine ring (335.0°) is in accordance with sp³ hybridization. Some atoms of the acetate group are disordered and were refined using a split model [occupancy ratio 0.673 (10):0.327 (10)].

(4′-Acet­yloxy-1,3,1′-trioxo-1,3,4,4a,4b,5,6,7,9,9a-deca­hydro­spiro­[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, mol­ecules are linked via C—H...O hydrogen bonds, forming two-dimensional networks lying parallel to the ab plane.