From herb of Lycopodium complanatum L., Lycopodiaceae: B"odeker, Ann. 208, 363 (1881). Structure: Harrison et al., Can. J. Chem. 39, 2086 (1961). Stereochemistry: Anet, Tetrahedron Lett. 1960, no. 20, 13. Synthesis of (±)-form: G. Stork et al., J. Am. Chem. Soc. 90, 1647 (1968); W. A. Ayer et al., ibid. 1648; C. H. Heathcock et al., ibid. 100, 8036 (1978); 104, 1054 (1982); D. Schumann et al., Ann. 1982, 1700. Review of synthetic studies: Stork, Pure Appl. Chem. 17, 383 (1968).