Abstract
From nutgrass, Cyperus rotundus (Cyperaceae), a new sesquiterpenic ketol has been isolated as the acetate and named sugeonol whose stereostructure I has been deduced from the following evidence. Spectral determinations of sugeonol and its acetate (II) indicate the presence of a 2-methyl-3-substituted-cyclopent-2-enone system. Chemical and physico-chemical properties of its derivatives (III and IV) have established that the hydroxyl group of sugeonol is situated at the γ-position of the α, β-unsaturated ketone system and in another cyclopentane ring. Oxidation of sugeonol with selenium dioxide has given the trione (VI) derived from cyperotundone (V) establishing the skeleton of sugeonol. The coupling constant between the C-6 and C-7 hydrogens shows the C-6 hydroxyl to be α-oriented.
