Crystal structure of (4bS,8aR)-1-isopropyl-4b,8,8-trimethyl-7-oxo-4b,7,8,8a,9,10-hexa­hydro­phenanthren-2-yl acetate

The title compound, C(22)H(28)O(3), was prepared by a direct acetyl­ation reaction of naturally occurring totarolenone. The mol­ecule contains three fused rings, which exhibit different conformations. The central ring has a half-chair conformation, while the non-aromatic oxo-substituted ring has a screw-boat conformation. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds and C—H⋯π inter­actions, forming sheets parallel to the bc plane. The carbonyl O atoms and the C atom at the 6-position of the cyclo­hexene ring are each disordered over two sets of sites with major occupancy components of 0.63 (7) and 0.793 (14), respectively.