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US 5,453,503 AGranted
Azetidinone intermediates to carbacephalosporins and process
AssigneeEli Lilly and Company
InventorsJames Aikins, John P. Gardner, Billy G. Jackson, John R. Rizzo, Eddie V. Tao
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 cis-3-(substituted amino)-1-(2-substituted 2-oxoethyl)-4-substituted azetidinones. The 7.beta.-amino-3-hydroxy-1-carba(1-dethia)-3-cephem-4-carboxylic acid esters are useful chiral intermediates to .beta.-lactam antibiotics.
Claims9
A process for preparing a compound of the formula ##STR11## wherein R.sup.1 is C.sub.1 -C.sub.6 alkyl;
- a phenyl group ##STR12## 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 ##STR13## 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.1 '0 wherein R.sup.1 ' represents C.sub.1 -C.sub.4 alkyl, C.sub.5 -C.sub.7 cycloalkyl, benzyl, nitrobenzyl, methoxybenzyl, or halobenzyl;
- and R.sup.2 is 4-nitrobenzyl, comprising reacting a compound of the formula ##STR14## wherein R.sup.1 and R.sup.2 are as defined above and R.sup.3 is a leaving group of the formula --OR.sup.4, wherein R.sup.4 is C.sub.1 -C.sub.6 alkyl, 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, and amido, with a lithium tertiary-alkoxide at a temperature of between about -25.degree. C. and about 27.degree. C.
1 more element
Dependencies are inferred from the claim text.