Patents Examined by Micahael L. Shippen
  • Method for producing 1-menthol
    Patent number: 6342644
    Abstract: Provided is a method for the production of 1-menthol, which comprises hydrogenation of piperitenone with a transition metal complex of a specified optically active phosphine to produce pulegone, hydrogenation of the obtained pulegone with a ruthenium-phosphine-amine complex in the presence of base to obtain pulegol, and further hydrogenation of the pulegol with a transition metal catalyst.
    Type: Grant
    Filed: May 7, 2001
    Date of Patent: January 29, 2002
    Assignee: Takasago International Corporation
    Inventors: Noboru Sayo, Takaji Matsumoto