title: 6,8-Dihy-droxy-8a-methyl-3,5-dimethyl-idenedeca-hydro-naphtho-[2,3-b]furan-2(3H)-one.
abstract: The title compound, C(15)H(20)O(4), is a eudesmanolide isolated from the Chinese medicinal plant Carpesium tris-te Maxim. The mol-ecule contains three rings, viz. two fused six-membered rings in chair conformations and a five-membered ring in a flattened envelope conformation. In the crystal, two hy-droxy groups are involved in the formation of intra- and inter-molecular O-H⋯O hydrogen bonds. The H atoms in these groups are split, with site-occupation factors of 0.5. The inter-molecular hydrogen bonds link mol-ecules into chains propagating in [010].
authors.affiliation: College of Life and Environment Science, Minzu University of China, Beijing 100081,  People's Republic of China.
authors.forename: Ting-Ting
authors.initials: TT
authors.lastname: Liu
authors.forename: Hai-Bo
authors.initials: HB
authors.lastname: Wu
authors.forename: Wen-Shu
authors.initials: WS
authors.lastname: Wang