An efficient synthesis of pyranonaphthoquinones is achieved by ethylenediamine diacetate-catalyzed reactions of 4-hydroxy-2-quinolones with a variety of α,β-unsaturated aldehydes in moderate yields. This method provides a rapid entry into biologically interesting α-lapachone derivatives with a variety of substituents on the pyran ring.
pyranonaphthoquinones - ethylenediamine diacetate - tandem Knoevenagel-electrocyclic reaction - α-lapachone derivatives
