Methyl (�)-10,11-epoxy-3,7,11-trimethyldodeca-trans-2,trans-6-dienoate (VI) has been synthesized, starting from 5,6-isopropylidenedioxy-6- methylheptan-2-one (II). Spectroscopic and gas chromatographic data for the cis,cis-,trans-, trans,cis-, and trans,trans-isomers of methyl 10,11-isopropylidenedioxy-3,7,11-trimethyldodeca-2,6-dienoate (X) are given.