Manufacture of high molecular weight unsaturated ketones by reacting allyl alcohols with 1-substituted butadiene-1-alkyl ethers or with 1-substituted butadiene-1-alkyl esters or with substances capable of forming said compounds under the conditions of the reaction, in the presence of acid catalysts at elevated temperatures and in the liquid phase. The resulting unsaturated ketones are precursors or intermediates in the manufacture of a variety of natural dyes such as zeaxanthin, rhodoxanthin and xanthophyll or of odorants such as damascones and damascenones.
The present invention relates to new bicyclic compounds as aroma chemicals. Specifically, it relates to the use of bicyclic aroma compounds as an aroma chemical and also for enhancing and/or modifying the aroma of a composition.