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:
Mar. 15, 2005
Filed:
Apr. 23, 2001
Pavel A. Krasutsky, Duluth, MN (US);
Pavel A. Krasutsky, Duluth, MN (US);
Regents of the University of Minnesota, Minneapolis, MN (US);
Abstract
The present invention provides a method for preparing an ester of betulin at the 3-position, e.g., betulin-3-acetate, including the selective alcoholysis of a betulin-3,28-diester, e.g., betulin-3,28-diacetate; a method for preparing betulin-3-acetate including (1) acetylating betulin to provide betulin-3,28-diacetate and (2) the alcoholysis of betulin-3,28-diacetate to provide betulin-3-acetate; and a method for preparing betulinic acid (1) acetylating betulin to provide betulin-3,28-diacetate, (2) the alcoholysis of betulin-3,28-diacetate to provide betulin-3-acetate, (3) oxidizing betulin-3-acetate to provide betulinic aldehyde-3-acetate, (4) oxidizing betulinic aldehyde-3-acetate to provide betulinic acid-3-acetate, and (5) deprotecting betulinic acid-3-acetate to provide betulinic acid.