A series of 6-aryl-2,4-dioxo-5-hexenoic acids, were synthesized and tested against HIV-1 in cell-based assays and against recombinant HIV-1 integrase (rIN) in enzyme assays. Compound 8a showed potent antiretroviral activity (EC 50=1.5 μM) and significant inhibition against rIN (strand transfer: IC50=7.9 μM; 3′-processing: IC50=7.0 μM). A preliminary molecular modeling study was carried out to compare the spatial conformation of 8a with those of L-731,988 (4) and 5CITEP (7) in the IN core. © 2004 Elsevier Ltd. All rights reserved.