74587-20-5Relevant articles and documents
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.
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.
