The structure of a furanosesquiterpene, atractylon, isolated from Atractylis ovata Thunb and Atractylodes japonica Koizumi, was established by Yosioka and his co-workers. As starting material for the synthesis of atractylon, 2,3,4,6,7,8-hexahydro-2-oxonaphthalene has been used, and 4,4a,5,6,7,8,8a,9-octahydro-3,8a-dimethyl-5-methylenenaphtho[2,3-b] furan has been synthesised. This racemic compound is identical with atractylon, by comparison of infrared spectra.