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The synthesis and structure-activity relationship (SAR) of novel and highly potent positive allosteric modulators of AMPA receptors, 3-biphenyl-4-yl-4-cyano-5-ethyl-1-methyl-1H-pyrrole-2-carboxylic acid, are described. These studies indicated that higher potency was achieved with ortho substitution of the distal (D) phenyl of the 3-biphenyl ring and resulted in the discovery of a potent pyrrole LY2059346 (23q), that was selected for further evaluation in in vitro native tissue assays and in vivo experiments.

The synthesis of (2Z,4RS)-5-acetamido-4-guanidino-2-benzamidopent-2-enoic acid (sodium salt) 5 is reported. Wittig–Horner olefination of diamino protected propionaldehyde 8 with phosphonoglycine trimethyl ester 11 provided (Z)-olefin methyl ester 12. The methyl ester was converted to allyl ester 15 by initial hydrolysis with lithium hydroxide followed by reaction with allyl bromide. Target compound 5 was prepared from allyl ester 15 by initial formation of bis(Boc)guanidino ester 16 followed by treatment with tetrakis(triphenylphosphine)palladium(0). The product was evaluated for activity against influenza neuraminidase and was found to be weakly active.

Novel noncoded D-amino acids have been combined with decahydroisoquinoline, octahydrothienopyridine, and urea hydroxyethylamine isosteres to provide potent HIV-1 protease inhibitors with excellent HIV-1 antiviral activity. LY314613 shows a promising combination of potency and oral bioavailability. Trends in the SAR and comparisons to other isostere derivatives will be discussed.

Using the hydroxyethylamine isosteres 1 and 2 containing the novel cis-octahydrothienopyridine moiety, substantial enhancement of binding potencies for HIV-1 protease inhibitors which incorporate carbamate linked heterocyclic P2 ligands has been realized. This increase in binding has led to a very potent antiviral compound (LY326188). The pharmacokinetics of selected derivatives are detailed in this report.

Replacement of the decahydroisoquinoline group contained in Ro 31-8959 by a cis -octahydrothienopyridine moiety has provided a high affinity hydroxyethylamine isostere for use in HIV-1 protease inhibitors. Further gains in potency have been realized by incorporation of a sulfur atom into the P 1 benzyl group. Modification by a key P 2 ligand provided LY316440, a potent, orally absorbed inhibitor of HIV-1 protease.

[reaction: see text]. A synthesis of stereochemically pure and orthogonally protected N-acetyl-(2-deoxy-2-aminoglucopyranosyl)-beta-[1,4]-N-acetylmuramyl (NAG-NAM) monopeptide (2), the glycopeptide core of lipid II and of the bacterial cell wall repeating unit, is reported.

The enhanced stability of the carbacephem nucleus over the corresponding cephalosporin nucleus has allowed the synthesis of 7-arylglycyl-3-trifluoromethyl-carbacephems. These unique carbacephems possess broad spectrum activity and high stability to both plasmid and chromosomally mediated s-lactamases.

Computational chemistry made possible the prediction of the three-dimensional structures of γ-lactam analogues of penems and carbapenems before the analogues were made. Molecular superpositioning showed that these novel structures with a 7β-acylamino side-chain present the pharmacophoric groups in close spatial similarity to the groups in biologically active cephalosporin and penicillin antibiotics. This suggests that 8-oxo-7-acylamino-1-azabicyclo[3.3.0]-oct-2-ene-2-carboxylates and the 4-thia-analogues can be accommodated in the same active sites of essential bacterial penicillin-binding proteins where cephalosporins and penicillins are recognized. The syntheses of these compounds are reported. The γ-lactams exhibit low, but detectable levels of antibacterial activity and suggest promise that substantial activity can be achieved with other γ-lactams.

γ-Lactam analogues of carbapenems have been synthesized using a [3+2] cyclization approach. Slight antibiotic activity was observed in one case.

Obtention de phenoxyacetamido-7 carbacepheme-3- et cepheme-3 carboxylates-4 et de phenoxyacetamido-7 carbacepheme-3 dicarboxylates-3,4