From Evodia rutaecarpa Hook. & Thoms and bark of Zanthoxylum rhetsa DC., Rutaceae: Y. Asahina, K. Kashiwaki, J. Pharm. Soc. Jpn. 1915, 1293, C.A. 10, 607 (1916); Gopinath et al., Tetrahedron 8, 293 (1960). Structure: Y. Asahina J. Pharm. Soc. Jpn. 1924, 1; Ohta, J. Pharm. Soc. Jpn. 65, 15 (1945), C.A. 45, 5697 (1951). Synthesis: Asahina, Ohta, Ber. 61B, 319 (1928); T. Kametani et al., J. Am. Chem. Soc. 98, 6186 (1976); eidem, Heterocycles 4, 23 (1976). Biosynthesis: M. Yamazaki et al., Tetrahedron Lett. 1966, 3221; 1967, 3317. Mass spec.: J. Tamas et al., Acta Chim. Acad. Sci. Hung. 89, 85 (1976).