Potassium nitrodisulfonate

Oxidation of l,3,3-trimethyl-2-methylenindolinone (64) with potassium nitrodisulfonate leads to a five-ring spiro product (65) (83CB1309). Enam-inoesters react with olefins in the presence of tetrabutylammonium cerium(IV) nitrate (TBACN) as the oxidizing agent the overall process proceeds via a cation radical and affords an enaminolactone (66)... 

Oxidation of 2,2-dimethylthiochroman-4-ones to the 3,4-diones is readily achieved with isoamyl nitrite <1994T7865> and 8-hydroxy-2,2-dimethylthiochroman-4-one with Fremy s salt, potassium nitrodisulfonate, yields the benzothiopyranoquinone 387. Following cycloaddition with a cyclohexa-1,3-diene, enolization, oxidation, and aromatization led to a naphtho[2,3-A]-thiopyranoquinone (Scheme 103) <1997TL153, 2000H(53)585>. 

Fremy s salt (potassium nitrodisulfonate) is a widely used reagent, particularly in the synthesis of quinone antibiotics. One example has emerged from Kozikowski s group in their approach to the rubra-dirin antibiotics. The MEM-protected 2-nitroresorcinol (4) was converted in several steps to the phenol... 

Nickel peroxide. Oxoperoxobis(N-phenylbenzohydroxamato) molyb-denum(VI). Palladium(II) acetate-Tri-phenylphosphine. Palladium /-butyl peroxide trifluoroacetate. Periodic acid. Permonophosphoric acid. Potassium dichromate. Potassium hydrogen persulfate. Pyridinium dichromate. Ruthenium tetroxide. Selenium dioxide. Sodium hypochlorite. Titanium(IlI) chlo-ride-Hydrogen peroxide. Potassium nitrodisulfonate. Potassium peroxodi-sulfate. Pyridinium chlorochromate. Pyridinium chlorochromate-Hydrogen peroxide. Sodium permanganate monohydrate. Tetra-n-Butylammonium periodate. Thailium(III) acetate. Trimethyl-amine N-oxide. Triphenylmethylphos-phonium permanganate. 

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