In coca leaves of various origin. Found in crude hygrine. Readily converted to hygrine by acids and bases. Isoln: Liebermann, Ber. 22, 679 (1898); Liebermann, Cybulski, ibid. 28, 578 (1895). Identity with bellaradine: Steinegger, Phokas, Pharm. Acta Helv. 30, 441 (1955). Structure: Hess, Fink, Ber. 53, 794 (1920); Sohl, Shriner, J. Am. Chem. Soc. 55, 3828 (1933); Rapoport, Jorgensen, J. Org. Chem. 14, 664 (1949). Synthesis: Sp"ath, Tuppy, Monatsh. Chem. 79, 119 (1948); Galinovsky et al., ibid. 82, 551 (1951). Enzymatic synthesis: Tuppy, Faltaous, ibid. 91, 167 (1960). Stereochemistry: Galinovsky, Zuber, ibid. 84, 798 (1953). Biosynthesis: E. Leete, Chem. Commun. 1980, 1170.