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. 15, 1995
Filed:
Dec. 30, 1993
Takasago International Corporation, Tokyo, JP;
Abstract
A process for for producing a (2R,3S)-cyclohexylnorstatine or a salt thereof is disclosed, which comprises the steps of: enantioselectively hydrogenating a 4-cyclohexyl-2-halogeno-3-oxobutyric acid ester in the presence of a ruthenium-phosphine complex to produce a 4-cyclohexyl-2-halogeno-(3R)-hydroxybutyric acid ester (2); epoxidizing the compound (2) in the presence of a base to produce a 4-cyclohexyl-(2S,3R)-epoxybutyric acid ester (3); reacting the compound (3) with a lower trialkylsilyl azide in the presence of a Lewis acid to produce a (3S)-azide-4-cyclohexyl-(2S)-substituted butyric acid ester (4); subjecting the compound (4) to hydrogenolysis to produce a (2S,3S)-cyclohexylnorstatine derivative (5); and inverting the configuration at the 2-position of the compound (5).