The l-form of laudanine, q.v. Traces in opium: Hesse, Ann. 282, 208 (1894); Kauder, Arch. Pharm. 228, 419 (1890). Structure and synthesis: Spth, Bernhauer, Ber. 58, 200 (1925); Spth, Seka, ibid. 1272; Spth, Burger, Monatsh. Chem. 47, 733 (1926); Frydman et al., Tetrahedron 4, 342 (1958). Configuration: Corrodi, Hardegger, Helv. Chim. Acta 39, 889 (1956).