Crystal structure of 15-(naphthalen-1-yl)-7,7a,8,9,10,11-hexahydro-6a,12a-(methanoepoxymethano)indolizino[2,3-c]quinoline-6,13(5H)-dione

In the title compound, C27H24N2O3, the dihedral angle between the mean planes of the dihydrofuran and 3,4-dihydroquinoline ring systems is 70.65 (9)°. The dihydrofuran ring adopts an envelope conformation with the C atom adjacent to the methylene C atom of the pyrrolidine ring as the flap. The five-membered pyrrolidine ring adopts a twist conformation on the N—C(tetrasubstituted) bond. In the crystal, molecules are linked via pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R 2 2(8) ring motif. The dimers are linked via pairs of C—H⋯O hydrogen bonds, forming ribbons enclosing R 2 2(12) ring motifs lying in a plane parallel to (01-1).

In the title compound, C 27 H 24 N 2 O 3 , the dihedral angle between the mean planes of the dihydrofuran and 3,4dihydroquinoline ring systems is 70.65 (9) . The dihydrofuran ring adopts an envelope conformation with the C atom adjacent to the methylene C atom of the pyrrolidine ring as the flap. The five-membered pyrrolidine ring adopts a twist conformation on the N-C(tetrasubstituted) bond. In the crystal, molecules are linked via pairs of N-HÁ Á ÁO hydrogen bonds, forming inversion dimers with an R 2 2 (8) ring motif. The dimers are linked via pairs of C-HÁ Á ÁO hydrogen bonds, forming ribbons enclosing R 2 2 (12) ring motifs lying in a plane parallel to (011).
The molecular structure of the title molecule is shown in Fig. 1. The furan ring system has an envelope conformation with atom C14 as the flap. The quinoline ring adopts a planar conformation with a maximum deviation of 0.326 (2) Å for the spiro C atom, C14. The five-membered pyrrolidine ring (N2/C13-C16) is twisted on N2-C13. The sum of the bond angles around atom N2 of the octahydroindolizine ring is 338.61° and for N1 of the quinoline ring it is 359.71°, confirming the sp 3 and sp 2 hybridization, respectively.

S2. Synthesis and crystallization
A mixture of methyl 2-((hydroxyl(naphthalene-2-yl) methyl) acrylate (1 mmol), isatin (1.1 mmol) and pipecolic acid (1.1 mmol) was placed in a round bottom flask and melted at 180°C until completion of the reaction was evidenced by TLC analysis. After completion of the reaction, the crude product was washed with 5 ml of ethylacetate and hexane mixture (1:4 ratio) which successfully provided the pure product as colorless solid. The product was dissolved in ethyl acetate and heated for two minutes. The resulting solution was subjected to crystallization by slow evaporation of the solvent for 48 hours resulting in the formation of single crystals.

S3. Refinement
Crystal data, data collection and structure refinement details are summarized in Table 1. All H atoms were fixed geometrically and allowed to ride on their parent C atoms, with C-H distances fixed in the range 0.93-0.98 Å with U iso (H) = 1.5U eq (C) for methyl H 1.2U eq (C) for other H atoms.

Figure 1
The molecular structure of the title compound, showing the atom labelling. Displacement ellipsoids are drawn at the 30% probability level.   Table 1 for details).  The molecular packing viewed along the a axis. Dashed lines shows the intermolecular C-H···O and N-H···O hydrogen bonds (see Table 1 for details).
15-(Naphthalen-1-yl)-7,7a,8,9,10,11-hexahydro-6a,12a-(methanoepoxymethano)indolizino[2,3- where P = (F o 2 + 2F c 2 )/3 (Δ/σ) max < 0.001 Δρ max = 0.17 e Å −3 Δρ min = −0.21 e Å −3 Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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.