| abstract |
A process for preparing a symmetrical, terminally ring-substitutednPolyens is a polyene di (O, O-dialkyl acetal) with a cyclic dienol ethernin the presence of a Lewis or Brönsted acid, the resultingnHydrogenation condensation product and produced by the at this stagenPolyene derivative under basic or acidic conditions to split off alcohol. FurthernAspects of the invention are the new cyclic dienol ethers, as well as the new,nresulting from the condensation intermediates and the other intermediatesnin this process. The end products are mainly carotenoids, thenfind appropriate use, e.g. as dyes and pigments for food,nAnimal products etc. |