Isoln from Dacrydium biforme Pilg., Podocarpaceae: Hosking, Brandt, Ber. 68, 1311 (1935); from the bled resin of Podocarpus ferrugineus, Podocarpaceae: Brandt, Neubauer, J. Chem. Soc. 1940, 683; from Pimus palustris Mill., Pinaceae: Harris, Sanderson, J. Am. Chem. Soc. 70, 2079, 2081 (1948). Identity of isopimaric and miropinic acids: Brossi, Jeger, Helv. Chim. Acta 33, 722 (1950). Structure: Antkowiak et al., J. Org. Chem. 27, 1930 (1962). Stereochemistry: Ireland, Newbould, ibid. 1931; Antkowiak et al., Can. J. Chem. 43, 1257 (1965); Bose et al., Indian J. Chem. 5, 228 (1967).