Patents by Inventor Takao Niki

Takao Niki 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).

  • Novel 1.alpha.-hydroxy-24-oxovitamin D.sub.3, its preparing process and the novel precursors thereof
    Patent number: 4199577
    Abstract: Novel 1.alpha.,3.beta.-dihydroxy-24-oxocholesta-5,7-diene and the hydroxyl group-protected derivatives thereof.Said novel 1.alpha.-hydroxy-24-oxovitamin D.sub.3 and said novel intermediates are also useful as the intermediates of 1.alpha.,24-dihydroxyvitamin D.sub.3.1.alpha.,3.beta.-Dihydroxy-24-oxocholesta-5,7-diene and the hydroxyl group-protected derivatives thereof are prepared from fucosterol via 1.alpha.,3.beta.-diprotected hydroxy-24(24)-ethylenedioxycholest-5-ene. 1.alpha.-hydroxy-24-oxovitamin D.sub.3 is prepared by irradiation with ultraviolet rays to 1.alpha.,3.beta.-dihydroxy-24-oxocholesta-5,7-diene or a hydroxyl group-protected derivatives thereof, isomerization using heat energy, and, when necessary, elimination of the protecting groups.
    Type: Grant
    Filed: September 1, 1978
    Date of Patent: April 22, 1980
    Assignee: Teijin Limited
    Inventors: Toru Takeshita, Takao Niki, Hiroyuki Kawashima, Kiyoshi Bannai