Synthesis of Chiral Odoriferous Oxy-Derivatives of 1,5,5-Trimethylcyclohexene.

Ten racemic and ten enantiomeric pairs of odoriferous compounds, mainly esters, were obtained from isophorone. The starting material, isophorone was reduced to racemic isophorol, which was resolved in pure enantiomers via the lipase catalyzed esterification. The next steps of syntheses, orthoacetic Claisen rearrangement, reduction of esters, esterification of alcohols or their oxidation were carried out with the racemic and enantiomerically enriched (above 98% ee) compounds. The propionates of isophorol (7, 7a, 7b) and 2-(l,5,5-trimethyl-2-cyclohexen-1-yl)ethanol (10, 10a, 10b) possess the most valuable odoriferous properties, useful for cosmetic and food industries.