Corymbolone

The title compound, C(15)H(24)O(2) [systematic name: (4S,4aR,6R,8aR)-4a-hy­droxy-4,8a-dimethyl-6-(prop-1-en-2-yl)octahydro­naphthalen-1(2H)-one], features two edge-shared six-membered rings with the hydroxyl and methyl substituents at this bridge being trans. One adopts a flattened chair conformation with the C atoms bearing the carbonyl and methyl substituents lying 0.5227 (16) and 0.6621 (15) Å, respectively, above and below the mean plane through the remaining four C atoms (r.m.s. deviation = 0.0145 Å). The second ring, bearing the prop-1-en-2-yl group, has a chair conformation. Supra­molecular helical chains along the b axis are found in the crystal packing, which are sustained by hy­droxy–carbonyl O—H⋯O hydrogen bonding.