From rhizome of Peucedanum ostruthium (L.) Koch (Imperatoria ostruthium L.) Umbelliferae: Herzog, Krohn, Arch. Pharm. 247, 553 (1909); Butenandt, Marten, Ann. 495, 187 (1932); from Prangos pabularia Lindl., Umbelliferae: Pigulevskii, Kuznetsova, Dokl. Akad. Nauk SSSR 61, 309 (1948), C.A. 43, 3416d (1949); from Flindersia bennettiana F. Muell., Rutaceae: Galbraith et al., Aust. J. Chem. 13, 427 (1960). Structure: Sp"ath, Pesta, Ber. 66, 754 (1933). Synthesis: Sp"ath, Holzen, ibid. 67, 264 (1934); Murayama et al., Chem. Pharm. Bull. 20, 741 (1972).