Found in feces of man and of carnivorous animals: Bondzynski, Humnicki, Z. Physiol. Chem. 22, 396 (1896); Wells et al., Arch. Biochem. Biophys. 57, 437 (1955); Samuel et al., J. Chromatogr. 14, 508 (1964). Prepn from coprostenone: Ruzicka et al., Helv. Chim. Acta 17, 1407 (1934); Shoppee, Summers, J. Chem. Soc. 1950, 687. From coprostenol: Sch"onheimer, Evans, J. Biol. Chem. 114, 567 (1936); Ruzicka et al., Helv. Chim. Acta 21, 498 (1938); Agashe, Summers, J. Chem. Soc. 1957, 3107; Dart, Henbest, ibid. 1960, 3563. Prepn from cholesterol: Rosenfeld, Gallagher, Steroids 4, 515 (1964).