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US 4,734,495 AGranted
Process and intermediates for beta-lactam antibiotics
AssigneePresident and Fellows of Harvard College
InventorsDavid A. Evans, Eric B. Sjogren
Life of this patent
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Abstract
1-Benzyl(or substituted benzyl)-3.beta.-[4(S)-aryloxazolidin-2-one-3-yl]-4.beta.-(2-arylvinyl)azet idin-2-ones are provided via cycloaddition of a 4(S)-aryloxazolidin-2-one-3-ylacetyl halide and an imine formed with a benzylamine and a 3-arylacrolein, e.g. cinnamaldehyde. The azetidinones are useful chiral intermediates in an asymmetric synthesis of 1-carba(1-dethia)-3-hydroxy-3-cephem-4-carboxylic acids and esters and to monocyclic .beta.-lactam antibiotics.
Claims7
A compound of the formula ##STR25## wherein R.sub.5 is amino or an acylamino group of the formula
- R.sub.1 CONH--
- wherein R.sub.1 is C.sub.1 -C.sub.6 alkyl;
- a phenyl group or substituted phenyl group of the formula ##STR26## wherein a and a' independently are hydrogen, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, or halogen;
- or R.sub.1 is a group of the formula ##STR27## wherein Z is O or S, m is 0 or 1, and a and a' have the same meanings as defined above;
- or R.sub.1 is R.sup.o.sub.1 --O-- wherein R.sup.o.sub.1 is C.sub.1 -C.sub.4 alkyl, C.sub.5 -C.sub.7 cycloalkyl, benzyl, nitrobenzyl, methoxybenzyl, or halobenzyl;
- and wherein alk is C.sub.1 -C.sub.4 alkyl.
3 more elements
Dependencies are inferred from the claim text.