2-(2-Naphthyl)-1,3-dioxane

The title compound, C14H14O2, crystallizes in the chiral monoclinic space group P21. This acetal is composed of a planar naphthalene ring with a 1,3-dioxane ring substituent, which has a chair conformation. In the crystal structure, symmetry-related molecules are connected via a weak C—H⋯O interaction to form a helical chain propagating in [010]. While there are no π–π stacking interactions present, there are weak C—H⋯π interactions involving the naphthalene aromatic rings, which link the helical chains to form a two-dimensional network in the (011) plane.

The title compound, C 14 H 14 O 2 , crystallizes in the chiral monoclinic space group P2 1 . This acetal is composed of a planar naphthalene ring with a 1,3-dioxane ring substituent, which has a chair conformation. In the crystal structure, symmetry-related molecules are connected via a weak C-HÁ Á ÁO interaction to form a helical chain propagating in [010]. While there are nostacking interactions present, there are weak C-HÁ Á Á interactions involving the naphthalene aromatic rings, which link the helical chains to form a twodimensional network in the (011) plane.
The structure of the title compound is illustrated in Fig. 1, and the geometrical parameters are given in the Supplementary information and the archived CIF. The bond lengths and angles are close to those in three similar compounds located in the Cambridge Crystal Structure Database (CSD, V 5.30, last update Sept. 2009;Allen, 2002). For example, methyl 2,3-di-Oacteyl-4,6-O-(2-naphthyl)methylene-α-D-galactopyranoside (Borbas et al., 2002), which also crystallized in the monoclinic space group P2 1 , and where the naphthalene ring is planar and the two six-membered rings in the galactopyranoside unit have chair conformations.
In the crystal of the title compound symmetry related molecules are connected via a C-H···O interaction (Table 1) Table 1 for details.

Refinement
In the final cycles of refinement, in the absence of significant anomalous scattering effects, 944 (93%) Friedel pairs were merged and Δf" set to zero. The H-atoms could all be located in difference electron-density maps. In the final cycles of refinement they were included in calculated positions and treated as riding atoms: C-H = 0.95-1.0 Å, with U iso (H) = 1.2U eq (parent C-atom). Using the one-circle Stoe Image Plate Diffraction System it is not always possible to measure 100% of the Ewald sphere, and here only 93.7% of the data were accessible out to 50° in 2θ. This has little effect on the bond distances and angles when comparing their values with those of the related structure mentioned above (Borbas et al., 2002). Fig. 1. A view of the molecular structure of the title compound, with displacement ellipoids drawn at the 50% probabilty level.  Table 1 for details].

Special details
Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles Refinement. In the final cycles of refinement, in the absence of significant anomalous scattering effects, 944 (93%) Friedel pairs were merged and Δf " set to zero. The H-atoms could all be located in difference electron-density maps. In the final cycles of refinement they were included in calculated positions and treated as riding atoms: C-H = 0.95 -1.0 Å, with U iso (H) = 1.2U eq (parent C-atoms).
Using the one-circle Stoe Image Plate Diffraction System it is not always possible to measure 100% of the Ewald sphere, and here only 93.7% of the data were accessible out to 50° in 2θ.