5′′-(2-Fluorobenzylidene)-1′-(2-fluorophenyl)-1′′-methyl-1′,2′,3′,5′,6′,7′,8′,8a’-octahydrodispiro[acenaphthylene-1,3′-indolizine-2′,3′′-piperidine]-2,4′′(1H)-dione

In the title compound, C37H32F2N2O2, the central six-membered piperidine ring adopts a twisted half-chair conformation, with the N and methylene C atoms deviating by −0.2875 (16) and 0.4965 (15) Å, respectively, from the mean plane defined by the other four atoms. The piperidine connected to the octahydroindolizine ring is in a half-chair conformation. The five-membered pyrrole ring adopts a slightly twisted envelope conformation with the piperidine C atom as the flap atom. The F and H atoms of both fluorobenzene rings are disordered, with occupancy factors of 0.941 (3):0.059 (3) and 0.863 (3):0.137 (3). The molecular structure features some intramolecular C—H⋯O interactions. In the crystal, a supramolecular zigzag chain sustained by C—H⋯F interactions parallel to the c axis is formed, generating a C(12) graph-set motif.

In the title compound, C 37 H 32 F 2 N 2 O 2 , the central sixmembered piperidine ring adopts a twisted half-chair conformation, with the N and methylene C atoms deviating by À0.2875 (16) and 0.4965 (15) Å , respectively, from the mean plane defined by the other four atoms. The piperidine connected to the octahydroindolizine ring is in a half-chair conformation. The five-membered pyrrole ring adopts a slightly twisted envelope conformation with the piperidine C atom as the flap atom. The F and H atoms of both fluorobenzene rings are disordered, with occupancy factors of 0.941 (3):0.059 (3) and 0.863 (3):0.137 (3). The molecular structure features some intramolecular C-HÁ Á ÁO interactions. In the crystal, a supramolecular zigzag chain sustained by C-HÁ Á ÁF interactions parallel to the c axis is formed, generating a C(12) graph-set motif.
The molecular structure features some intramolecular C-H···O interactions.
In the crystal structure, a zigzag supramolecular chain sustained by a C-H···F interaction, generating a graph-set motif of C 1 1 (12), parallel to the c axis, is formed (Fig. 2).

Refinement
H atoms were placed in calculated positions and allowed to ride on their carrier atoms, with C-H = 0.93-0.98 Å, and with U iso = 1.2U eq (C) for CH 2 and CH groups and U iso = 1.5U eq (C) for the CH 3 group. The two F and two H atoms of the fluorobenzene rings are disordered over two sets of sites in the ratios 0.941 (3) parameters were equated by dummy atom constraints using the EADP command]. Also, FLAT and DFIX restraints were used to stabilize the refinement of the disordered atoms.

Figure 1
The molecular structure of (I), showing 30% probability displacement ellipsoids and the atom-numbering scheme.

Special details
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.