| abstract |
A process for the manufacture of compounds of the general formula ##STR1## wherein R 1 signifies hydroxy or an etherified hydroxy group, and of zeaxanthin by converting a compound of the general formula ##STR2## wherein R 1 has the above significance, in an inert organic solvent into the acetylenide and reacting this with methyl vinyl ketone, reducing the alcoholate obtained or the alcohol (obtained after hydrolysis of the alcoholate) of the general formula ##STR3## wherein R 1 has the above significance, and subsequently hydrolyzing to give the compound of formula IV and, if desired, converting the compound of formula IV obtained into zeaxanthin. |