# 2006 International Union of Crystallography All rights reserved In the crystal structure of the title compound, C16H18N2O2, the indole moiety is nearly planar. The two carbonyl groups are almost perpendicular, with a torsion angle of 105.7 (4) , and the single C—C bond linking the two carbonyl groups is 1.515 (5) Å in length. The molecules are linked together by N—H O intermolecular hydrogen ...

The title compound, C(17)H(27)BrO(5), DEB, is a derivative of artemisinin which is used in malara therapy. The OR-group at C12 is cis to the CH(3)-group at C11 and axially oriented on ring D which has a chair conformation. The crystal packing is stabilized by several weak inter-molecular C-H⋯O inter-actions, which combine to form a C-H-O bonded network parallel to (001).

In the crystal structure of the title compound, C(9)H(11)BrO(2), mol-ecules are stacked parallel to the b-axis direction, forming double layers in which the molecules are arranged head-to-head, with the bromo-methyl groups pointing towards each other.

Generally, rotational isomerization about the carbon-carbon single bond in simple ethane derivatives in room-temperature solution under thermal equilibrium conditions has been too fast to measure. We achieved this goal using two-dimensional infrared vibrational echo spectroscopy to observe isomerization between the gauche and trans conformations of an ethane derivative, 1-fluoro-2-isocyanato-et...