From gum-resin of Olea europaea L., Oleaceae. Isoln: Pelletier, Ann. Chim. Phys. 51, 196 (1833). Structure: Traverso, Gazz. Chim. Ital. 90, 792 (1960); Smith, Tetrahedron Lett. 1963, 991. Revised structure: Ayres, Mhasalkar, ibid. 1964, 335; eidem, J. Chem. Soc. 1965, 3586.