1. N,N'-[(1S,2S)-Cyclo-hexane-1,2-di-yl]bis-(4-methyl-benzene-sulfonamide)
Yi-Ling Hong, Hua-Jie Tan, Liang Shen Acta Crystallogr Sect E Struct Rep Online. 2011 May 1;67(Pt 5):o1121. doi: 10.1107/S1600536811012372. Epub 2011 Apr 13.
In the title compound, C(20)H(26)N(2)O(4)S(2), the cyclo-hexane ring has a chair conformation. The two chiral C atoms are in S configurations. In the crystal, inter-molecular N-H⋯O hydrogen bonds link the mol-ecules into chains propagating in [001]. Weak inter-molecular C-H⋯O hydrogen bonds further stabilize the crystal packing.
2. (1S,2S,4R)-3,3-Dichloro-4,8,12,12-tetra-methyl-tricyclo-[5.5.0.0]dodeca-6,8-diene
Ahmed Benharref, Lahcen El Ammari, Moha Berraho, Esaadia Lassaba Acta Crystallogr Sect E Struct Rep Online. 2010 Aug 28;66(Pt 9):o2463. doi: 10.1107/S1600536810034070.
The title compound, C(16)H(22)Cl(2), a derivative of β-himachalene, was semi-synthesized from natural essential oils of Cedrus atlantica. The mol-ecule is built up from two fused six- and seven-membered rings. The six-membered ring has a perfect chair conformation, whereas the seven-membered ring displays a screw boat conformation; the dihedral angle between the rings is 46.48 (9)°.