From the rhizome of sedoary, Curcuma zedoarie Roscoe (Zingiberaceae), three new fursn-con--tsining sesquiterpenoids of the elemane type have been isolated. It is shown in the present communication that these sesquiterpenoids nov designated es curzerenone, epicurzerenone, and isofuranogeneaorene *1 *2 have structures I, II, and III, respectively. Curzerenone, C15Hle02, [a], a*, is revealed by its UV, IR, and BMR spectra to contain a carbonyl involved in a B-furoyl system (A=r 272 mu, vm= 1675 cm-'), an a-hydrogen and a S-methyl on a furan ring, a methylene flanked by quaternq carbons and weakly coupled with the a-hydrogen of the furan, a tertiary methyl, 8 vinyl on a quaternary carbon, an isopropenyl, and an isolated hydrogen. Partial hydrogenation of curzerenone over R%ney-nickel in methanol resulted in the saturation of the vinyl group yielding the dibydro-derivative (IV), which was further hydrogenated with platinum in methanol to furnish the tetrahydro-derivative (V). Curserenone must thus be represented as in formula I (disregarding the stereochemistry).
Epicurserenone, cl5%8o29 Ear&, p9 possesses very similar spectral properties to those of curzerenone. Indeed, the UV, IR, and maea spectra of both substances are practically identical