Patents Assigned to Ishahara Sangyo Kaisha Ltd
  • Method for isomerization of trans-form 2-methylspiro (1,3-oxathiolane-5,3') q
    Patent number: 4861886
    Abstract: A method for isomerization of trans-form 2-methylspiro(1,3-oxathiolane-5,3')quinuclidine or acid addition salts thereof, which comprises isomerizing said trans-form quinuclidine or acid addition salts thereof to cis-form 2-methylspiro(1,3-oxathiolane-5,3')quinuclidine or acid addition salts thereof in the presence of at least one acid catalyst selected from the group consisting of an organic sulfuric acid, a halide functioning as a Lewis acid, and sulfuric acid.
    Type: Grant
    Filed: July 6, 1988
    Date of Patent: August 29, 1989
    Assignee: Ishahara Sangyo Kaisha Ltd
    Inventors: Takahiro Haga, Itaru Shigehara, Toru Koyanagi, Kazutoshi Hara, Masaru Maeda