Acta Crystallographica Section E (Jan 2011)
(3R,6R,12R,20S,24S)-3,6,12-Triacetyl-20,24-epoxydammarane-3,6,12,25-tetraol
Abstract
The title compound, C36H58O8, was prepared from 20(S)-protopanaxatriol, which was degraded from Panax quinquefolium saponin with sodium in glycerine, extracted and seperated by flash chromatography. Three six-membered rings are in chair conformations, the five-membered ring is in an envelope form and the tetrahydrofuran ring has a conformation intermediate between half-chair and envelope. In the crystal, molecules are linked by O—H...O hydrogen bonds, and C—H...O contacts also occur. The absolute structure was assigned on the basis of the synthesis.