(1RS,2RS,3RS)-1,2-Dimethoxy-3-methyl-2-phenyl-1-(2-thienyl)cyclopropane

In the title compound, C16H18O2S, a new cis-1,2-dimethoxycyclopropane, the two methoxy groups are in a cis configuration and in trans positions with respect to the H atom and the phenyl and thienyl rings on the cyclopropyl group. The molecular packing is dominated by weak intermolecular C—H⋯O interactions, allowing the formation of zigzag chains propagating parallel to the c axis. The dihedral angle between the aromatic rings is 86.12 (8)°.

In the title compound, C 16 H 18 O 2 S, a new cis-1,2-dimethoxycyclopropane, the two methoxy groups are in a cis configuration and in trans positions with respect to the H atom and the phenyl and thienyl rings on the cyclopropyl group. The molecular packing is dominated by weak intermolecular C-HÁ Á ÁO interactions, allowing the formation of zigzag chains propagating parallel to the c axis. The dihedral angle between the aromatic rings is 86.12 (8) .

Related literature
For related literature on the chemistry, see: Lebel et al. (2003). For a general overview of the biological implications of cyclopropane-related derivatives, see: de Meijere et al. (2003). For their occurrence, see: Wessjohann et al. (2003).  Table 1 Hydrogen-bond geometry (Å , ).
Financial support from the Spanish Ministerio de Educacion y Ciencia (MAT2006-01997 and 'Factoría de Cristalizació n' Consolider Ingenio 2010) and FEDER funding is acknowledged.

Comment
The cyclopropane ring is a quite common subunit of natural products isolated from plants, fungi, and microorganisms (Wessjohann, et al. 2003). Many of these natural products show biological activity, and some of them have found applications as drugs or insecticides (de Meijere et al., 2003). Classical chemical synthesis of cyclopropane derivatives include the halomethyl-metal mediated cyclopropanation of olefins, the transition-metal-catalyzed carbene-transfer reaction from diazo compounds, and the nucleophilic-addition/ring-closing sequence (Lebel et al. 2003). A new method for the synthesis of cis-1,2-dimethoxycyclopropane through the cyclopropanation of lithium ketone enolates with Fischer carbene complex will be published elsewhere. The molecular structure of the title compound is shown in Fig After 5 mins, cooling bath was removed and the reaction mixture was stirred for 30 min while allowing the temperature to reach 273 K. The reaction mixture was quenched with NH 4 Cl (20 ml). The resulting mixture was diluted with hexanes/ethyl acetate, 10/1 (110 ml) and subjected to air oxidation under sunlight. After 2-12 h the suspension was filtered through Celite and extracted with diethyl ether (3 x 10 ml). The organic layers were combined, dried over anhydrous Na 2 SO 4 and concentrated in vacuo. The crude product was purified by flash column chromatography on silica gel (hexanes/ethyl acetate, 20/1) to yield the title compound (277 mg, 77%) as a 1:1 diastereoisomer mixture of the all-S (1,2,3) and all-R forms.

Refinement
At the end of the refinement the highest peak in the electron density was 0.47 e Å -3 . The deepest hole was -0.52 e Å -3 .