1-Cyclohexylsulfinyl-2-methylnaphtho[2,1-b]furan

In the title compound, C19H20O2S, the cyclohexyl ring adopts a chair conformation and the arylsulfinyl unit is positioned equatorial relative to the cyclohexyl group. In the crystal, molecules are linked through weak intermolecular C—H⋯O hydrogen bonds. The O atom of the sulfinyl group is disordered over two orientations with site-occupancy factors of 0.923 (3) and 0.077 (3).

In the title compound, C 19 H 20 O 2 S, the cyclohexyl ring adopts a chair conformation and the arylsulfinyl unit is positioned equatorial relative to the cyclohexyl group. In the crystal, molecules are linked through weak intermolecular C-HÁ Á ÁO hydrogen bonds. The O atom of the sulfinyl group is disordered over two orientations with site-occupancy factors of 0.923 (3) and 0.077 (3).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FL2340).  (Einhorn et al. , 1984, Hranjec et al., 2003, Mahadevan & Vaidya, 2003. As a part of our ongoing studies of the substituent effect on the solid state structures of 2-methylnaphtho[2,1-b]furan analogues (Choi et al., 2006(Choi et al., , 2007, we report herein the crystal structure of the title compound. In the title molecule ( Fig. 1), the naphthofuran unit is essentially planar, with a mean deviation of 0.014 (1) Å from the least-squares plane defined by the thirteen constituent atoms. The cyclohexyl ring is in the chair form and arylsulfinyl moiety is positioned equatorial relative to the cyclohexyl group. The O atom of the sulfinyl group is disordered over two positions with site-occupancy factors, from refinement, of 0.923 (3) (part A) and 0.077 (3) (part B). The crystal packing ( Fig. 2) is stabilized by weak intermolecular C-H···O hydrogen bonds; the first one between a methyl H atom and and one of the disordered sulfinyl oxygen atoms (Table 1; C13-H13B···O2B i ), and the second one between a cyclohexyl H atom and the other disordered sulfinyl oxygen (Table 1; C14-H14···O2A ii ).

Experimental
77% 3-chloroperoxybenzoic acid (291 mg, 1.3 mmol) was added in small portions to a stirred solution of 1-cyclohexylsulfanyl-2-methylnaphtho[2,1-b] furan (355 mg, 1.2 mmol) in dichloromethane (40 mL) at 273 K. After being stirred at room temperature for 8h, the mixture was washed with a saturated sodium bicarbonate solution and the organic layer was separated, dried over magnesium sulfate, filtered and concentrated at reduced pressure. The residue was purified by column chromatography (hexane-ethyl acetate, 4:1 v/v) to afford the title compound as a colorless solid [yield 74%, m.p. 429-430 K; R f = 0.61 (hexane-ethyl acetate, 4:1 v/v)]. Single crystals suitable for X-ray diffraction were prepared by slow evaporation frroomm acetone at room temperature

Refinement
All H atoms were positioned geometrically and refined using a riding model, with C-H = 0.95 Å for aryl, 1.00 Å for methine, 0.99 Å for methylene and 0.98 Å for methyl H atoms, respectively. U iso (H) =1.2U eq (C) for aryl, methine and methylene, and

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.