Crystal structure of a bioactive sesquiterpene isolated from Artemisia reticulata

The title compound, C15H24O2 {systematic name: 1-[6-hy­droxy-7-(propan-2-yl)-4-methyl­idene-2,3,3a,4,5,6,7,7a-octa­hydro-1H-inden-1-yl]ethanone} was iso­la­ted from A. reticulata by column chromatography over silica gel by gradient solvent elution. The mol­ecule comprises a bi­cyclo­[4.3.0]nonane ring bearing acet­oxy, hy­droxy and isopropyl substituents, and an exocyclic double bond on the cyclo­hexane ring. In the bicyclic skeleton, the cyclo­hexane ring adopts a chair conformation ring and the cyclo­pentane ring is in an envelope conformation. In the crystal, mol­ecules are linked by O—H⋯O hydrogen bonds, forming chains along [010]. These chains are cross-linked by C—H⋯O hydrogen bonds.