Quinol tautomer

The pKa method was first used by Tucker and Irvin to determine the proportion of the tautomers of quinol-4-one present at equilibrium and was subsequently applied to many other potentially tautomeric hydroxy compounds " these results are summarized in Table I. 

Such a phenol keto-tautomer equivalent strategy was used for conjugate reduction of cyclic enones (equation 5). The quinone monoketals 9 and para-quinol ethers 10 were used as precursors to keto-tautomer equivalents of substituted phenols, namely enones 11, which were prepared by action of bis(2,6-di-fert-butyM-methylphenoxy)methylaluminium (MAD), followed by addition of lithium tri-iec-butyl borohydride (L-Selectride). The enones 11 obtained are reasonably stable at a freezer temperature without aromatization. ... 

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