The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 16, 1983
Filed:
Oct. 16, 1981
Csaba Szantay, Budapest, HU;
Lajos Szabo, Budapest, HU;
Gyorgy Kalaus, Budapest, HU;
Janos Sapi, Budapest, HU;
Janos Kreidl, Budapest, HU;
Maria Farkas nee Kirjak, Budapest, HU;
Andras Nemes, Budapest, HU;
Laszlo Cibula, Budapest, HU;
Richter Gedeon Vegyeszeti Gyar Rt., Budapest, HU;
Abstract
The invention relates to a new enantioselective synthesis for the preparation of optically active 14-oxo-E-homo-eburnane derivatives of the formula (Ia) ##STR1## wherein R.sup.1 is alkyl having from 1 to 4 carbon atom. In the synthesis optically active 6-alkoxycarbonylhexahydroindoloquinolizinium salts are employed as starting materials, which contain a center of chirality at the site of attachment of the carboxyl group. This center of chirality preserves the optical activity of the optically active tryptophan ester from which this compound has been prepared until a new center of chirality is formed in the molecule in a configuration corresponding to the desired end product. The carboxyl group, which is not needed in the end product and only serves to preserving the optical activity can then be eliminated. Compounds of the formula (Ia) are known in the art and may be used in the synthesis of (+)-vincamine and (+)-apovincaminic acid ethylester.