Abstract
It was deduced from the spectral data of callicarpone (I), the tetraol (IV), the chloro-hydrin (VII) and the anhydro-diacetyl derivative (II) that I was_??_tricarbocyclic diterpene having an ene-l, 4-dione and an α-hydroxy-isopropyl attached to an oxide ring. The struc-ture of the rearranged product obtained by treatment with sodium carbonate was established to be IX by converting it to 11-methoxy-ferruginol methyl ether. As this rearrangement was assumed to be initiated by proton abstraction by base, the structure I was required for callicarpone to explain the formation of IX.
