The title compound, C(19)H(24)O(6), is a sesquiterpene lactone isolated from the Kenyan plant Warburgia ugandensis. Ring A adopts a chair conformation, ring B is in a C(2) twist conformation and the lactone ring is nearly planar with maximum deviation 0.007 (1) Å. The reported absolute configuration is based on that of the similar compound bromo-parasiticolide A and is supported by analysis of Bijvoet differences from light atoms in Mo Kα radiation.