Four isomeric methyl substituted DCK analogues (2–5) were asymmetrically synthesized from different starting materials. 3-Methyl, 4-methyl, and 5-methyl-3′, 4′-di-O-(−)- camphanoyl-(+)-cis-khellactone (2–4) all were extremely potent against HIV-1 replication in H9 lymphocyte cells with EC50 and therapeutic index values of< 4.23× 10− 7 μM and> 3.72× 108, respectively, which are much better than those of DCK and AZT in this assay.
