A facile synthesis of naturally occurring binaphthoquinones: efficient oxidative dimerization of 4-alkoxy-1-naphthols using silver (II) oxide–40% nitric acid
…, M Hashimoto, S Morishita, M Hamada, N Kai, T Nagai
Oxidation of 4-alkoxy-1-naphthols with AgO–40% HNO3 occurred along with a dimerization to give the corresponding bi-1, 4-naphthoquinones. The oxidative dimerization required one hydroxyl group and took place at its ortho position. This reaction was applicable to syntheses of naturally occurring binaphthoquinones, bivitamin K3 and 3, 3′-bijuglone.
