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US 5,646,275 AGranted
Azetidinone intermediates to carbacephalosporins and process
AssigneeEli Lilly and Company
InventorsJohn P. Gardner, Billy G. Jackson
Life of this patent
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Abstract
7.beta.-Amino-3-hydroxy-1-carba(1-dethia)-3-cephem-4-carboxylic acid esters are provided via cyclization of compounds of Formula IIA below. ##STR1## The 7.beta.-Amino-3-hydroxy-l-carba(1-dethia)-3-cephem-4-carboxylic acid esters are useful chiral intermediates in the synthesis of .beta.-lactam antibiotics.
Claims11
A compound of the formula ##STR12## wherein R.sup.1 is C.sub.1 -C.sub.6 alkyl;
- a phenyl group ##STR13## wherein a and a' independently are hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy or halogen;
- a group represented by the formula ##STR14## wherein Z is O or S, m is 0 or 1, and a and a' have the same meanings as defined above;
- or R.sup.1 is R.sup.11 O wherein R.sup.11 represents C.sub.1 -C.sub.4 alkyl, C.sub.5 -C.sub.7 cycloalkyl, benzyl, nitrobenzyl, methoxybenzyl, or halobenzyl;
- R.sup.2 is a carboxy protecting group;
- and
- R.sup.3 is a leaving group of the formula --OR.sup.4, wherein R.sup.4 is C.sub.2 -C.sub.6 alkenyl, phenyl, or phenyl substituted with one, two or three substituents selected from C.sub.1 -C.sub.6 alkylthio, nitro, halo, carboxy.
3 more elements
Dependencies are inferred from the claim text.