2,4,5-trihydroxy-3-methylacetophenone: A cellulosic chromophore as a case study of aromaticityAuthor(s): Nele Sophie Zwirchmayr; Thomas Elder; Markus Bacher; Andreas Hofinger-Horvath; Paul Kosma; Thomas Rosenau
Source: ACS Omega
Publication Series: Scientific Journal (JRNL)
Station: Southern Research Station
Download Publication (267.0 KB)
DescriptionThe title compound (2,4,5-trihydroxy-3-methylacetophenone, 1) was isolated as chromophore from aged cellulosic pulps. The peculiar feature of the compound is its weak aromatic system that can be converted into nonaromatic (quinoid or cyclic aliphatic) tautomers, depending on the conditions and reaction partners. In alkaline media, the participation of quinoid canonic forms weakens aromaticity, whereas in neutral and acidic media, the strong hydrogen bond between the 2-hydroxyl group and the acetyl moiety plays an important role in favoring quinoid tautomers. As a result, compound 1, with quinoid contributions being already “preset”, is relatively stable toward oxidation and hardly undergoes alkylation or nitration at CH-6, whereas the 2,4,5- trimethoxyderivative, being “properly” aromatic and even more sterically hindered, is readily alkylated or nitrated. The lability of the aromatic system is best demonstrated by the unusual reaction of 1 with hydroxylamine, producing a tetroxime that is derived from its 2,4,5-triketo tautomer. The high oxidative stability and low reactivity of the compound hinder oxidative bleaching of this chromophore in cellulosic pulps and detection reactions for analytical purposes.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
CitationZwirchmayr, Nele Sophie; Elder, Thomas; Bacher, Markus; Hofinger-Horvath, Andreas; Kosma, Paul; Rosenau, Thomas. 2017. 2,4,5-trihydroxy-3-methylacetophenone: A cellulosic chromophore as a case study of aromaticity. ACS Omega. 2(11): 7929-7935. https://doi.org/10.1021/acsomega.7b00874.
- Degradation of the cellulosic key chromophores 2,5- and 2,6-dihydroxyacetophenone by hydrogen peroxide under alkaline conditions. Chromophores in cellulosics, XVII
- Insights into degradation pathways of oxidized anhydroglucose units in cellulose by β-alkoxy-elimination: a combined theoretical and experimental approach
- A review of lignin hydrogen peroxide oxidation chemistry with emphasis on aromatic aldehydes and acids
XML: View XML