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:
Oct. 24, 1989
Filed:
Sep. 11, 1987
Shigeo Nozoe, Sendai, JP;
Tomihisa Ohta, Sendai, JP;
Ajinomoto Co., Inc., Tokyo, JP;
Abstract
Novel amino acid derivatives of the formula ##STR1## wherein R.sup.1 is a protecting group removable under reducing or acid conditions, and R.sup.2 and R.sup.5 are hydrogen or carboxylic protecting groups, are useful as intermediates in preparing stereospecific carbapenam/carbapenem derivatives. R.sup.1 is removed under reducing conditions to form a pyrrolidine derivative, which is further cyclized from the R.sup.5 .dbd.H compound to form a .beta.-lactam ring. Stereospecificity at the 6-position is achieved by treatment with lithium diisopropylamide (LDA) and quenching at different termperatures. Compound (I) can be prepared by treating R.sup.1 -protected R.sup.3 -pyrrolidone carboxylic acid R.sup.2 -ester with a lithium enolate of the formula R.sup.4 CHLiCO.sub.2 R.sup.5. The lithium enolate can be formed from R.sup.4 CH.sub.2 CO.sub.2 R.sup.5 by treatment with LDA.