Synthesis of juglone derivatives. Hydroxy, acetyl and ethyl substituents

Article abstract of DOI:10.1016/0040-4020(69)80052-9

A number of hydroxyjuglones were prepared by the Thiele-Winter reaction onjuglone derivatives and by hydroxylation with ethanol-hydrochloric acid: 2-hydroxy, 3-hydroxy, 2,7-dihydroxy, 3,7-di-hydroxy, 6-acetyl-2-hydroxy, and 6-acetyl-3-hydroxyjuglone. By reductive acetylation of hydroxyjuglones, followed by Fries rearrangement and oxidative hydrolysis several acetyljuglones, and from them ethyljuglones by sodium borohydride reduction, were synthesized: 3-acetyl-2-hydroxy, 6-acetyl-2,3-dihydroxy, 6-acetyl-2,7-dihydroxy, and 6-acetyl-2,3,7-trihydroxyjuglone. Several of the newly synthesized compounds had previously been isolated from sea urchin spines.