e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
Tetrahedron letters
Regiospecificity in the reaction of 2, 3-dichloronaphthazarins with azide anions. Synthesis of echinamine A—a metabolite produced by the sea urchin Scaphechinus …
ND Pokhilo, AY Yakubovskaya, VA Denisenko…
Index: Pokhilo, Nataly D.; Yakubovskaya, Alla Ya.; Denisenko, Vladimir A.; Anufriev, Victor Ph. Tetrahedron Letters, 2006 , vol. 47, # 9 p. 1385 - 1387
It was found that 6-hydroxy-and 6-alkoxy-2, 3-dichloronaphthazarins react smoothly with sodium azide in methanol to produce the corresponding 2-azido derivatives as single regioisomers. We have explored the utility of this reaction for the synthesis of echinamine A (3-amino-7-ethyl-2, 5, 6, 8-tetrahydroxy-1, 4-naphthoquinone)—the first marine aminated hydroxynaphthazarin, a metabolite of the sea urchin Scaphechinus mirabilis (Agassiz).