Preparation of zeaxanthin, intermediates for this preparation, and the preparation thereof

摘要: Preparing (3R, 3'R)-zeaxanthin of the formula I ##STR1## starting from (4-hydroxy-2,2,6-trimethylcyclohexanone II ##STR2## via novel intermediates (4R,6R)-1-formyl-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptane IV ##STR3## (4R,6R)-1-(3-oxo-1-butenyl)-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptane V ##STR4## (4R,6R)-1-(3-hydroxy-3-methyl-1,4-pentadienyl)-2,2,6-trimethyl-7-oxabicyclo[2.2.1]heptane VI ##STR5## [5-(4R,6R)-(4-hydroxy-2,2,6-trimethyl-1-cyclohexylidene)-3-methyl-1,3-pentadienyl]triarylphosphonium salt iso-III ##STR6## where Ar is aryl and X one equivalent an anion a strong acid. The obtained by reacting ketone with dichloromethyllithium, which can be prepared metallation dichloromethane butyllithium or lithium diisopropylamide.