Facile, protection-free, one-pot synthesis of aureusidin.

A new, reliable, and convenient protection-free one-pot method for the synthesis of aureusidin (1) is described. The present synthetic approach involves the condensation of 4,6-dihydroxybenzofuranone with 3,4-dihydroxybenzaldehyde in the presence of concentrated HCl to afford aureusidin (1) in good yield with high purity. This procedure offers a short and simple route for the preparation of aureusidin (1), a bioactive natural product from several vegetal species, as well as for synthesis of other aurones.