Antibiotic substance produced by a strain of Streptomyces griseus (Krainski) Waksman et Henrici. Isoln and structure: Ettlinger et al., Helv. Chim. Acta 42, 563 (1959). Crystal structure: Jensen, J. Antibiot. 22, 231 (1969). Activity: Von Daehne et al., ibid. 233. Manuf process: Gaumann et al., US 3014922 (1961 to Ciba). Total synthesis: Schmidt, Geiger, Ann. 664, 168 (1963); Büchi, Lukas, J. Am. Chem. Soc. 86, 5654 (1964); Hagio, Yoneda, Bull. Chem. Soc. Jpn. 47, 1484 (1974); J. E. Ellis et al., J. Org. Chem. 42, 2891 (1977).