4α,6α-Dihydroxy-1β-methylsulfonyl-8α,9α-epoxy-2β,12-epoxymethano-β-dihydroagarofuran

The title molecule, C16H24O8S, is a dihydroagrofuran derivative and has a heteropolycyclic structure. One cyclohexane ring exhibits a chair conformation and the other a non-chair conformation. In the crystal structure there is an intermolecular C—H⋯O hydrogen-bonding interaction to stabilize the packing.

The title molecule, C 16 H 24 O 8 S, is a dihydroagrofuran derivative and has a heteropolycyclic structure. One cyclohexane ring exhibits a chair conformation and the other a non-chair conformation. In the crystal structure there is an intermolecular C-HÁ Á ÁO hydrogen-bonding interaction to stabilize the packing.  4 ,6 -Dihydroxy-1 -methylsulfonyl-8 ,9 -epoxy-2 ,12-epoxymethano--dihydroagarofuran J. Zhang, P. Gao, L. Li and W. Wu Comment Dihydroagrofuran esters and their derivatives have been widely explored as insecticidal medicine (Gao et al. 2007;Spivey et al. 2002). As a result of our program of screening insecticidal activity constituents from plants of China, some insecticidal β-dihydroagrofuran sesquiterpene polyol esters were isolated from the root bark of Chinese bittersweet, Celastrus angulatus Max. In order to find a new synthetic insecticide, the /b-dihydroagrofuran sesquiterpene polyol ester was optimized as a lead compound and we obtained an intermediate compound C 16 H 24 O 8 S (I) and the synthesis and structure are reported here.

Related literature
The title compound has a hetero-polycyclic structure. The 6-membering ring (C1-C6) exhibits a chair conformation.
The molecules of I crystalized in the P2 1 2 1 2 1 space group. In the crystal structure there is an intermolecular C-H···O hydrogen-bonding interaction (Table 1), which is helpful to the stabilization of the packing. Symmetry code: x, 1+y, z.

Experimental
A mixture of dihydroagarofuran (3.34 g, 10 mmol) and methanesulfonyl chloride (3.5 mL, 44 mmol) in dry Pyridine (20 mL) was stirred over night at room temperature. When the reaction was completed, 2 mL methol was added to the reaction mixture to quench the reaction, then 50 mL water was added to the mixture and it was extracted with ethyl acetate. The ethyl acetate layer was washed with 50 mL of water, 15 mL of saturated sodium chloride and dried over anhydrous sodium sulfate and was separated on a silica gel column chromatography with a gradient of petroleum ether and ethyl acetate as eluent to yield 1.87 g of the title compound. The compound was then dissolved in THF, and colorless crystals were formed on slow evaporation at room temperature over one week.

Refinement
All H atoms were placed in geometrically calculated positions and refined using a riding model with C-H = 0.93 Å and N-H = 0.86 Å and with U iso (H) = 1.2U eq (C, N). Fig. 1. The molecular structure of the title compound with the atom numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

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.  (3) O7-S1 1.427 (2) C9-C10 1.478 (4) O8-S1 1.4201 (18) C9-H9 0.9800