776-33-0Relevant academic research and scientific papers
Rearrangements of cyclobutenones. Synthesis of benzoquinones from 4-alkenyl-4-hydroxycyclobutenones
Perri, Steven T.,Moore, Harold W.
, p. 1897 - 1905 (2007/10/02)
The rearrangement of 4-alkenyl-4-hydroxycyclobutenones to quinones and related aromatic compounds is described. This rearrangement is complimentary to the previously reported ring expansions of 4-aryl- and 4-alkynyl-4-hydroxycyclobutenones. The synthetic scope and utility of the reaction are discussed. It is employed as a key step in the synthesis of a number of benzoquinones as well as in the total synthesis of the natural product, (±)-O-methylperezone and its regioisomer, (±)-O-methylisoperezone as well as coenzyme Q0 and aurantiogliocladin.
The Electron Spin Resonance Spectra of Semiquinones obtained from Some Naturally Occurring Methoxybenzoquinones
Holton, Dolores M.,Murphy, David
, p. 1757 - 1760 (2007/10/02)
Radical anions of methoxyquinones and related compounds were generated in a static system in alkaline media.The unpaired electron distribution in these radicals could not be satisfactorily verified by simplified SCF calculations.It is shown that a simple relationship exists between splittings in semiquinones and corresponding splittings in the closely related alkyl aryl ether radical cations.The relationship correlates very closely with the exsess charge effect which has been examined quantitatively for aromatic hydrocarbon radical ions, indicating that the same effect is operative in the oxygenated radicals, in which the splittings of the cations are ca. 20percent greater than corresponding splittings in the anions.These correlations, together with observed smooth variations of splitting patterns with substitution have permitted unambiguous assignment of the coupling constants of radicals such as the fumigatin anion or the 1,2-methylenedioxynaphthalene cation, without recourse to new computation.
