Zur Kenntnis der sesquiterpenoiden C12‐Ketone des ätherischen Öls von Vetiveria zizanioides (L.) Nash

Two new C12‐ketones, (+)‐(1S, 10R)‐1,10‐dimethylbicyclo[4.4.0]dec‐6‐en‐3‐one (5) and (+)‐(6S, 10S)‐6,10‐dimethylbicyclo[4.4.0]dec‐1‐en‐3‐one (6), have been isolated from Reunion vetiver oil (Vetiveria zizanioides (L.) Nash). Structure and absolute configuration of 5 were established by a four‐step synthesis from (+)‐isonootkatone ((+)‐α‐vetivone) (1). The structure of 6 followed from its spectroscopic properties and was confirmed by direct comparison with an authentic racemic sample. The absolute configuration of 6 was established by chemical correlation with (+)‐α‐eudesmol (13).