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:
Jun. 08, 1976
Filed:
Nov. 26, 1974
Hansuli Wehrli, Reinach, CH;
Oskar Jeger, Zollikerberg, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
The invention is for a selective reduction of the 20- oxo group in .DELTA..sup.16 -steroid-14.beta.,18-diol-20-ones of the pregnane series to form the two epimeric 20-alcohols having the 20 S and 20 R configuration. The process is especially intended for the manufacture of alkaloids of the batrachotoxin type, particularly for batrachotoxinine A, which is a pregnane derivative having a 20 S alcohol grouping, and epimers and derivatives, such as epi-batrachotixinine A or 7,8-dihydrobatrachotoxinine A. The process is characterized by reducing the said .DELTA..sup.16 -steroid-14.beta.,18-diol-20-ones in form of their 14,18-ketals, for instance the 14,18 acetonides and using appropriate complex light metal hydrides and operating at appropriate temperatures. The separation of the two isomers is easy and can be effected by the usual physical operations, such as crystallization or chromatography. In the 14.beta.,18,20-triols obtained the 18-hydroxy group can be dehydrogenated to the corresponding 18-aldehydes, which are intermediates necessary in the synthesis of the said pharmacological interesting substances, such as batrachotoxin, by treatment with a sulphoxide in the presence of a carboxylic acid anhydride.