Naphthoquinones Nickel

A new synthetic route to alkyl-substituted quinones has relied on the photochemical reaction of 2,3-dichloro-l,4-naphthoquinone with a thiophene derivative (77CL851). Irradiation of a benzene solution of the quinone and thiophene by a high pressure mercury lamp gave photoadduct (295) in 56% yield. Desulfurization of this compound over Raney nickel (W-7) gave the 2-butyl-1,4-naphthoquinone derivative (296 Scheme 62). Alkyl-substituted quinones such as coenzyme Q and vitamin K, compounds of important biological activity, could possibly be prepared through such methodology. 

Conjugate addition of acyl groups to naphthoquinones (3, 211).2 The acyl nickel carbonylate anion (1) undergoes conjugate addition to the ethylene ketal 2 to form a lithium adduct that can be trapped by allyl iodide to give 3 in 81% yield. This product can be converted in a few steps to the hydroxyquinone 4, a precursor of the naphthoquinone antibiotic deoxyfrenolicin (5). 

Naphthacenequinones, 19, 439 Naphthalene oxides, 130 Naphthazarin, 56, 57 Naphthohydroquinones, 368 1,4-Naphthoquinone, 18-19, 289 1-a-Naphthylethylamine, 320-321 1-(1-Naphthyl)ethyl isocyanate, 321 Nazarov reaction, 314, 499 Nerolidol, 292 Neryl acetate, 388 Nickel-Alumina, 321-322 Nickel boride, 190 Nickel(II) bromide, 136 Nickel(II) bromide-Zinc, 322 Nickel peroxide, 322-323 Nishimura catalyst, 408... 

Nickel peroxide, which is readily obtainable, has proved to be a useful oxidation agent Permanganate oxidation is an effective general method for the conversion of aliphatic nitro into oxo compounds a,/3-Ethyleneketones as well as 1,4-naphthoquinones can be cheaply and safely epoxidized with hypochlorite A rapid direct preparation of peroxy acids in methanesulfonic acid has been published An efficient method for the oxidative removal of the methyl group in position 19 of steroids has been described The application of hydride transfer for carboxylations has been continued. 

Ci Hi3NNi09S 1.5 H2O, Tetraaquo(1,2-naphthoquinone-1-oximato-6-sulphonate)nickel(II) sesquihydrate, 43B, 1357 Cl Hi4CdCl2N802, Dichloro-bis(1-methylcytosine)-cadmium(lI), 45B,... 

Co, Ni, Pd, Tl, or Zn, 311 Thiosemicarbazide, polymers with 5,8-dihydroxy- 1,4-naphthoquinone and nickel formate, 215 Titanyl phosphinate polymers,... 

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