Isoln from Chondodendron tomentosum Ruiz & Pav., Menispermaceae: Wintersteiner, Dutcher, Science 97, 467 (1943); King, J. Chem. Soc. 1948, 1945; Bick, Clezy, ibid. 1960, 2402; Boissier et al., Lloydia 28, 191 (1965), C.A. 64, 948b (1966). Structure: Dutcher, J. Am. Chem. Soc. 68, 419 (1946); Hultin, Acta Chem. Scand. 15, 1130 (1961). Configuration: Bick, Clezy, J. Chem. Soc. 1953, 3893; Hultin, Acta Chem. Scand. 17, 753 (1963). Revised structure: Everett et al., Chem. Commun. 1970, 1020. 13C-NMR: L. Koike et al., J. Org. Chem. 46, 2385 (1981).