Synthese und Chiralität der stereoisomeren Achillene,Achillenole und Hymentherene

(+)-cis-Achillene ( 10 ) and (?)-trans-achillenol (7), two monoterpenes recently isolated 1] from the essential oil of Achilleafilipendulina, were synthesized, together with their stereoisomers (?)-(9) and (+)-(8), starting from (S)-(+)-2,6-trans-dimethylocta-1,3, 7-triene ( 1 ). The isomeric ß-hymen thereties ((?)- 3 and (+)-4), often quoted 2] 3] 4] but never isolated, were obtained as intermediates. The mode of synthesis chosen establishesis (R)-chirality for naturally occurring (?)-trans-achillenol (7) and (+)-cis-achillene ( 10 ) as well as for the purely synthetic 4, 7-diene derivatives described in this paper.