The corrected structure of rosmaridiphenol, a bioactive diterpene from Rosmarinus officinalis

From the aerial parts of a Chilean sample of Rosmarinus officinalis L., a diterpene was isolated whose spectroscopic data and physical constants were coincident with that of rosmaridiphenol. However, careful examination of the spectroscopic data and chemical reactions led to a different structure, where the carbonyl function has to be placed at C-1 instead of C-20. The correct structure of rosmaridiphenol should therefore be changed to 11,12-dihydroxy-8,11,13-icetexatrien-1-one.