PROCESS FOR THE MANUFACTURE OF 6,10-DIMETHYLUNDECAN-2-ONE, ISOPHYTOL, ALPHA-TOCOPHEROL (ACETATE) AND FURTHER INTERMEDIATES THEREOF

摘要

The present invention is directed to a process for the manufacture of 6,10-dimethylundecan-2-one comprising the step of hydrogenating (5Z)-nerylacetone with hydrogen in the presence of a catalyst, whereby the catalyst is capable of preferentially hydrogenating carbon-carbon double bonds over carbon-oxygen double bonds. Preferably the catalyst comprises a metal selected from the group consisting of palladium, platinum, rhodium, iridium and nickel and mixtures thereof. The 6,10-dimethylundecan-2-one obtained according to the process of the present invention may be used as starting material for isophytol and α-tocopherol (acetate) via 3,7,11-trimethyl-dodec-1-en-3-ol ("tetrahydronerolidol"; THNL), 6,10,14-trimethylpentadec-5-en-2-one ("(5E/5Z)-5,6-dehydro-C18-ketone") and 6,10,14-pentadecane-2-one ("C18-ketone") or alternatively via 3,7,11-trimethyl-dodec-1-yn-3-ol, 6,10,14-trimethylpentadec-4,5-dien-2-one ("C18-allene-ketone") and 6,10,14-pentadecane-2-one ("C18-ketone"). Thus, the present invention is also directed to such processes which comprise the step of hydrogenating (5Z)-nerylacetone according to the process of the present invention.