Eriobrucinol (1) has been related to hydroxyeriobrucinol (4) by oxidation of the methyl ether of the latter to a ketone (8) and desulphurisation of the derived thioketal. The structures of the coumarins are derived from chemical and spectroscopic arguments. Assignment of the all cis configuration for the alicyclic system is supported by evidence for conformational inversion in the 1' hydroxy derivative (11). The structure of the coumarin bruceol, which had been isolated from Eriostemon brucei F. Muell. was described in an early part of this series. More recently we have reexamined extracts of the plant and isolated three new coumarins. One of these had spectral properties suggesting that it may be desoxybruceol and it was identified by comparison with synthetic racemic material. The other coumarins which are phenolic have been named eriobrucinol (1) and hydroxyeriobrucinol (4) and are the basis of this paper.