7330-85-0Relevant articles and documents
Dienone tautomers of 4-alkoxy-2,6-di-terf-butylphenols
Omura, Kanji
, p. 7156 - 7161 (2007/10/03)
Generation and isolation of 4-alkoxycyclohexa-2,5-dienones 9, the tautomeric forms of the title phenols (10), is described. They are generated efficiently by the Ag ion mediated reaction of 4-bromocyclohexa-2,5-dienone 3b with simple alcohols, although they can be irreversibly isomerized into 10 under the reaction conditions. Crude materials with high amounts of 9 can be obtained by conducting the reaction with AgClO4 in the presence of Na2CO3 or with AgOCOCF3 and by interrupting the reaction shortly after the formation of 9 is complete. The AgOCOCF3 reaction produces labile 4-(trifluoroacetoxy)cyclohexa-2,5-dienone 11 also, the formation of which becomes significant as the alcohol becomes bulky. All of 9 prove to be very much susceptible to the prototropic rearrangement into 10 by catalysis with base, acid, or SiO2. Crude dienones 9 can be conveniently prepared directly from phenol 6 by treatment for a short time with Br2 in alcohols containing AgClO4 and Na2CO3. A one-pot synthesis from 6 of 4-oxyfunctionalized 2,6-di-tert-butylphenols, including 10, is also described.
Reactions of the 2,6-Di-tert-butyl-4-(N-tert-butylnitrono)-phenoxyl Radical
Schulz, Manfred,Bach, Barbara,Reinhardt, Michael
, p. 579 - 587 (2007/10/02)
The title compound, a phenoxyl radical containing a nitrono group, reacts with alcohols and tert-butylhydroperoxide yielding phenol and products of secondary solvent reactions.The reactions with lead tetraacetate, tert.-butoxy and 2-cyanoisopropyl radicals give high yields of cyclohexadienone adducts (6, 7 and 10) containing unchanged nitrono function.The reaction with dibenzoylperoxide, however, leads to the modification of the nitrono group yielding the N-benzoyloxycarboxamide (8).In the acidic decomposition of the tert-butoxy radical adduct we suggest a nitrenium ion (16) as an intermediate.
