Process for the Preparation of (3E, 7E)-Homofarnesol

A process for preparing compounds of the general formula I

• in which
• R1 is a straight-chain or branched, optionally mono- or polyunsaturated hydrocarbyl radical, and R2 is H or C1-C6-alkyl, which comprises
• a) reacting a carbonyl compound of the formula II
• in which R1 and R2 have the meanings given above,
• by means of Wittig olefination to give a cyclopropane of the general formula (III)
• in which R1 and R2 have the meanings given above,
• b) reacting the cyclopropane of the formula III with ring opening, to give a compound of the formula IV
• in which R1 and R2 have the meanings given above, and X is halogen or O—R′, in which R′ is H, acyl, Tf-acetyl or SC2—R″, in which R″ is alkyl or aryl;
• and
• c) converting the compound of the general formula IV to the compound of the general formula I.