Phenol–dienone Rearrangement in the Reactions of Phenols

Abstract

The paper presents a combination of theoretical and experimental results which show that the sustainment phase of a driven Reversed-Field Pinch (RFP) configuration is not fundamentally limited in time by toroidal field diffusion. Driven ZT-40M discharges where the external poloidal voltage circuit does not directly maintain toroidal field reversal are examined. Flux measurements on slowly rising current discharges clearly show that a toroidal flux regeneration mechanism (referred to as the 'dynamo-effect') must be present. Numerical simulations demonstrate that this effect is operative in the plasma on a short timescale <0.1 ms. This result is shown to be independent of the form of the resistivity profile. Thus, the possibility that the experimental results can be explained without a dynamo mechanism, if the temperature in the vicinity of the toroidal field reversal point is sufficiently high, is eliminated. Implications of these facts with regard to theoretical stability and transport studies of the RFP are discussed.

Voltammetric Determination of Nitro Derivative of Synthetic Antioxidant 2,6-di-tert-butyl-4-methyl-phenol

“…The reaction probably proceeds as reported by Ley and Müller (1956). The side products of the hydrolysis are o-and p-quinones (Ershov, Volodkin, and Bogdanov 1963).…”

“…Similar methods of preparation of these compounds were also described by Ershov and Zlobina (1963), Ershov, Volodkin, andBogdanov (1963), andWaring (1966). An interesting nitration of trialkylphenols is presented in Ershov and Zlobina (1964) in which a saturated aqueous solution of NaNO2 was used instead of nitric acid.…”

13C nuclear magnetic resonance spectra of some bromo- and methyl-substituted cyclohexa-2,5-dienones

“…(ii) Values of ' J involving the methyl groups (Tables 3-5). The values for the couplings within the 2-methyl group (Table 3) cover the range 128.9-131.0 Hz, and are slightly lower for those compounds (l), (3), and (5) having adjacent hydrogen than for the remainder with adjacent bromine.…”

“…Thus for compounds in which R is methyl and E is nitro, the conversion shown in equation ( 2) is easily accomplished. When both R and E can be detached as nucleophiles, such dienones are readily converted into quinones [equation (3)]. Little is known about the mechanism of these displacements.…”

ipso Nitration. XXIV. Nitration of 2-methylphenols. Formation and rearrangement of 6-methyl-6-nitrocyclohexa-2,4-dienones

“…Nitration of 2,4,6 trisubstituted phenols often gives nitrodienones (2,3). Normally the 2,5-dienone is formed, although formation of a 2,4-dienone has been reported (4).…”