74587-20-5Relevant academic research and scientific papers
Benzoquinones and Related Compounds. Part 6. Addition of Benzenesulfinic Acid to Substituted 1,4-Quinones
Bruce, J. Malcolm,Lloyd-Williams, Paul
, p. 2877 - 2884 (2007/10/02)
Benzenesulfinic acid adds to 1,4-quinones in the presence of trifluoroacetic acid affording phenylsulfonylhydroquinones.Addition occurs predominantly at the 6-position for methyl-, tert-butyl- and trifluoromethyl-1,4-benzoquinone, but at the 5-position for methoxy-1,4-benzoquinone.Addition to acyl-1,4-benzoquinones occurs exclusively at the 3-position, but under similar conditions phenylsulfonyl-1,4-benzoquinone affords a mixture of 2,3- and 2,6-bisphenylsulfonylhydroquinones, although the former becomes the sole product in the presence of an excess of trifluoraceticacid.These results are rationalised in terms of selective protonation of the quinone.Oxidation of the phenylsulfonylhydroquinones yields the corresponding quinones which with 1,3-dienes give the expected Diels-Alder adducts.
An Electron Spin Resonance Investigation of the 2-Pivaloyl-1,4-benzoquinone Radical Anion
Flint, Nicholas J.,Tabner, Brian J.
, p. 97 - 102 (2007/10/02)
The 2-pivaloyl-1,4-benzoquinone radical anion has been prepared both by electrochemical reduction (in dimethylformamide) and by alkali-metal reduction (in tetrahydrofuran).The e.s.r. spectrum observed in dimethylformamide is that of a single species.However, in tetrahydrofuran the nature of the spectra depend on the alkali-metal counter-ion.For example, linewidth variation is observed when K+ is the counter-ion whilst two separate species are observed when Li+ is the counter-ion.The results of these experiments indicate that the various species result from different locations of the alkali-metal counter-ion adjacent to the radical anion rather than from rotational comformers resulting from the rotation of the pivaloyl group.
Benzoquinones and Related Compounds. Part 2. Preferred Conformations of Some Acyl-1,4-benzoquinones in Solution
Bruce, Malcolm,Heatley, Frank,Ryles, Roderick G.,Scrivens, James H.
, p. 860 - 866 (2007/10/02)
Studies based on polarographic reduction potentials, electronic absorption spectra, and (1)H and (13)C nuclear magnetic relaxation data show that in solution the preferred conformation of formyl-1,4-benzoquinone is that with the formyl and quinonoid groups coplanar, and the formyl carbonyl group anti to the 1-carbonyl, whereas that of acetyl- and pivaloyl-1,4-benzoquinone has the acyl groups approximately perpendicular to the quinonoid ring.
