From Aconitum fischeri Reich. and A. sachalinense F. Schmidt, Ranunculaceae: Makoshi, Arch. Pharm. 247, 243 (1909); Majima, Morio, Ber. 57, 1472 (1924). Structure: Ochiai et al., J. Pharm. Soc. Jpn. 75, 545 (1955); Keith, Pelletier, Chem. Commun. 1967, 993 (corr. ibid. 1968, 1739); eidem, J. Org. Chem. 33, 2497 (1968).