Patents by Inventor Yukio Narabe

Yukio Narabe 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).

  • Terpene derivatives and process for preparing the same
    Patent number: 5245060
    Abstract: A terpene derivative represented by the general formula (I): ##STR1## wherein R.sup.1 represents a lower alkyl group; R.sup.2 represents an alkyl group, a cycloalkyl group, a cycloalkylalkyl group, an aryl group, an arylalkyl group or a heteroaryl group; n is 0 or 1 or 2; and the symbol " " represents a single or double bond with the proviso that both of the linkages adjacent to each other are not simultaneously single bonds or double bonds which are useful for the preparation of drug, food, perfume and so on, and a process for preparing thereof.
    Type: Grant
    Filed: March 12, 1992
    Date of Patent: September 14, 1993
    Assignee: Eisai Co. Ltd.
    Inventors: Kimio Hamamura, Yoshio Urawa, Yukio Narabe, Yoshihiko Hisatake, Shizumasa Kijima
  • Process for the preparation of terpenes
    Patent number: 5073659
    Abstract: A terpene compound having the formula (III) is produced by reacting an allylic halide having the formula (I) with a Grignard reagent having the formula (II) in the presence of anhydrous zinc chloride and a copper compound or an organic zinc halide compound having the formula (IV) in the presence of a copper compound, provided that when A-A is C-C, R' is hydrogen and when A-A is C=C, X is chlorine.
    Type: Grant
    Filed: August 10, 1990
    Date of Patent: December 17, 1991
    Assignee: Eisai Co., Ltd.
    Inventors: Kichisaburo Hamamura, Yutaka Ohnuki, Yukio Narabe, Yoshihiro Hisatake, Takashi Banba, Shizumasa Kijima