摘要:
The Echinacea-derived immunostimulator and HIV-1 integrase inhibitor (-)-chicoric acid (=2,3-bis([3(3,4-dihydroxyphenyl)-1-oxoprop-2-enyl]oxy)butanedioic acid; 1a) was conveniently prepared via a silane-promoted Pd-mediated chemoselective hydrogenolysis of its perbenzylated derivative 12a, which was generated from an efficient and reliable carbodiimide-mediated coupling reaction between the caffeic acid dibenzyl ether derivative 7 and commercially available (+)-dibenzyl L-tartrate (9a). The other naturally occurring dextrorotatory chicoric acid (1b) can be similarly prepared.