Curzerenone, C15H18O2, [α]D ±0°, a main component in the essential oil of Curcuma Zedoaria, was found to have a planar structure Ia, on the basis of its mass, ultraviolet (UV), and nuclear magnetic resonance (NMR) spectra, along with spectral data of dihydro- and tetrahydro-curzerenone, and the perbenzoic acid oxidation product of I. Catalytic hydrogenation of I with platinum black in acetic acid gave two epimeric isomers (XII and XIII) of eleman-6-one. These facts show that the stereostructure of curzerenone can be written as I.
