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:
May. 15, 1990
Filed:
Sep. 11, 1987
Edib Jakupovic, Nykvarn, SE;
Roy T Sourander, Sodertalje, SE;
Jan U Stenhede, Sodertalje, SE;
Rolf P Svensson, Ronninge, SE;
Astra Pharmaceutical Production Aktiebolag, Sodertalje, SE;
Abstract
A method of controlling the epimeric distribution in the preparation of 16,17-acetals of pregnane derivatives characterized in reaction of a corresponding 16,17-acetonide with an aldehyde or ketone in (a) hydrocarbon solvent wherein the solubility of the pregnane derivative is less than 1 mg/l or in a halogenated hydrocarbon solvent together with a hydrohalogen acid or an organic sulphonic acid as catalyst and in the presence of small grains of an insert material in the reaction medium or (b) a halogenated hydrocarbon solvent together with a hydrohalogen acid an organic sulphonic acid as catalyst and in the presence of an epimeric distribution modifier.