3α-Hydr-oxy-ent-atis-16-en-14-one.

The title compound, C(20)H(30)O(2), is an ent-atisane diterpenoid which was isolated from the roots of Euphorbia kansuensis. The mol-ecule contains five six-membered rings, among which three six-membered rings of the bicyclo-[2.2.2]octane unit adopt boat conformations and two cyclo-hexane rings adopt chair conformations. In the crystal structure, mol-ecules are connected by inter-molecular O-H⋯O hydrogen bonds, forming zigzag chains propagating parallel to [001].