Patents by Inventor Robert K. Muller

Robert K. Muller has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Cyclohexenone derivatives and process for making same
    Patent number: 4585885
    Abstract: A silyl-enol ether of the formula ##STR1## wherein n stands for the number and X stands for a group ##STR2## or n stands for the number 1 and X stands for the 6,11-dimethylhexadeca-2,4,6,8,10,12,14-heptaene-2,15-diyl group, the symbols R.sup.1 have the same or different significances and denote alkyl groups, and the symbol R.sup.2 represents a trialkylsiloxy group --OSi(R.sup.1).sub.3 or an ether group,is oxidized with percarboxylic acid and, if desired, the resulting .alpha.-siloxy ketone is hydrolyzed to an .alpha.-hydroxy ketone. This process is especially suitable for the manufacture of astaxanthin.
    Type: Grant
    Filed: August 19, 1983
    Date of Patent: April 29, 1986
    Assignee: Hoffmann-La Roche Inc.
    Inventors: Kurt Bernhard, Robert K. Muller, Robert Spruijtenburg
  • Process for producing astaxanthin
    Patent number: 4245109
    Abstract: The compound 5[4(acyloxy or protected hydroxy-3-oxo-2,6,6-trimethyl-cyclohex-1-en-1-yl)-3-methyl-penta-1,4-dien- 3-ol], an intermediate for the coloring agent astaxanthin, its conversion to astaxanthin and its preparation from 4-oxo-.beta.-ionone including intermediates in this synthesis.
    Type: Grant
    Filed: May 21, 1979
    Date of Patent: January 13, 1981
    Assignee: Hoffmann-La Roche Inc.
    Inventors: Hans J. Mayer, Robert K. Muller