Preparation of astaxanthin novel intermediates therefor and the preparation thereof
AssigneeBASF SE
InventorsHansgeorg Ernst, Walter Dobler, Joachim Paust, Udo Rheude
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Abstract
Compounds of the formula I ##STR1## where R.sup.1 is H or C.sub.1 -C.sub.4 -alkyl, R.sup.2 is C.sub.1 -C.sub.4 -alkyl and R.sup.3 is an ether, silyl ether or acetal protective group which can be converted into a hydroxyl group by hydrolysis, in particular one of the radicals ##STR2## and a process for preparing these compounds by reacting an alkenyne of the formula II ##STR3## in an inert solvent in the presence of lithium amide with a cyclohexenone of the formula III ##STR4## and the use of the compounds of the formula I for preparing astaxanthin, are described.
Claims2
A compound of the formula I ##STR33## where R.sup.1 is H or C.sub.1 -C.sub.4 -alkyl,
- R.sup.2 is C.sub.1 -C.sub.4 -alkyl and
- R.sup.3 is an ether, silyl ether or acetal protective group which can be converted into a hydroxyl group by hydrolysis.
Dependencies are inferred from the claim text.