Enones of formulae Ia-d undergo cyclization to give stereoselectively the enol esters IIa-d, respectively, IIa-d are suitable synthones for some sesquiterpene syntheses.—In this paper the synthesis of torreyol (1) is described by an all step stereocontrolled reaction sequence: cyclization educt 10 (Ic) was prepared by alkylation of 8 with 5 and enol ether cleavage of 9. The reaction sequence 11a (IIc)→ 14a 15→ 18 (ester hydrolysis, formation of the tert. ...