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:
Dec. 28, 1993
Filed:
Aug. 06, 1991
Peter Schneider, Bottmingen, CH;
Gerardo Ramos, Arlesheim, CH;
Ciba-Geigy Corporation, Ardsley, NY (US);
Abstract
The invention relates to a novel process for the manufacture of (3R,1'R)-4-acyloxy-3-(1'-hydroxyethyl)-2-azetidinones of formula ##STR1## in which R.sup.1 represents lower alkyl or aryl, by enantioselective reduction of the carbonyl group in a suitable .alpha.-acylaminomethyl-acetoacetic acid ester, cyclisation of the resulting .alpha.-acylaminomethyl-.beta.-hydroxybutyric acid ester to a 5,6-dihydro-1,3,4H-oxazine with inversion of the carbon atom carrying the hydroxy group, equilibration to form the preferred trans-substituted dihydrooxazine, recleaving to form the configuratively uniform .alpha.-aminomethyl-.beta.-hydroxybutyric acid, ring-closure to form the .beta.-lactam and oxidative acylation at C(4) of the .beta.-lactam. Compounds of formula I can be used as starting materials for the manufacture of .beta.-lactam antibiotics. The invention relates also to novel intermediates.