Methyl 4-phenyl-1,2,3,3a,4,4a,5,12c-octahydronaphtho[1′,2′:3,2]furo[5,4-b]pyrrolizine-4a-carboxylate

In the title compound, C26H25NO3, both pyrrolidine rings adopt envelope conformations, whereas the dihydropyran ring adopts a half-chair conformation. The phenyl ring is oriented at an angle of 27.9 (1)° with respect to the naphthalene ring system. An intramolecular C—H⋯O hydrogen bond is observed. The crystal packing is stabilized by weak intermolecular C—H⋯π interactions.

In the title compound, C 26 H 25 NO 3 , both pyrrolidine rings adopt envelope conformations, whereas the dihydropyran ring adopts a half-chair conformation. The phenyl ring is oriented at an angle of 27.9 (1) with respect to the naphthalene ring system. An intramolecular C-HÁ Á ÁO hydrogen bond is observed. The crystal packing is stabilized by weak intermolecular C-HÁ Á Á interactions.
The molecular structure is influenced by an intramolecular C-H···O hydrogen bond. The crystal packing is stabilized by weak intermolecular C-H···π interactions (( Table 1).

Refinement
H atoms were placed in idealized positions and allowed to ride on their parent atoms, with C-H = 0.93, 0.98, 0.97 and 0.96 Å for aromatic, methine, methylene and methyl H respectively, and Uiso(H) = 1.5U eq (C) for methyl H and Uiso(H) = 1.2U eq (C) for all other H atoms.

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 > σ(F 2 ) is used only for calculating Rfactors(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.