- Detection of an O-methyltransferase synthesising acetosyringone in methyl jasmonate-treated tobacco cell-suspensions cultures
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Acetosyringone (3′,5′-dimethoxy-4′-hydroxyacetophenone) is a well-known and very effective inducer of the virulence genes of Agrobacterium tumefaciens but the precise pathway of its biosynthesis in plants is still unknown. We have used two tobacco cell lines, cultured in suspension and exhibiting different patterns of accumulation of acetosyringone in their culture medium upon treatment with methyl jasmonate, to study different steps of acetosyringone biosynthesis. In the two cell lines studied, treatment with 100 μM methyl jasmonate triggered a rapid and transient increase in acetovanillone synthase activity followed by a progressive increase in S-adenosyl-L-methionine: 5-hydroxyacetovanillone 5-O-methyltransferase activity which paralleled the rise in acetosyringone concentration in the culture medium. This O-methyltransferase displayed Michaelis-Menten kinetics with an apparent Km value of 18 μM for 5-hydroxyacetovanillone and its activity was magnesium-independent. Its molecular mass was estimated by gel permeation on an FPLC column and was found to be of ca. 81 kDa. 5-Hydroxyacetovanillone was the best substrate among the different o-diphenolic compounds tested as methyl acceptors in the O-methyltransferase assay. No formation of 5- hydroxyacetovanillone could be detected in vitro from 5-hydroxyferuloyl-CoA and NAD in the extracts used to measure acetovanillone synthase activity, indicating that 5-hydroxyacetovanillone is probably formed by direct hydroxylation of acetovanillone rather than by β-oxidation of 5-hydroxyferulic acid. Taken together our results strongly support the hypothesis that acetosyringone biosynthesis in tobacco proceeds from feruloyl-CoA via acetovanillone and 5-hydroxyacetovanillone.
- Negrel, Jonathan,Javelle, Francine,Wipf, Daniel
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Read Online
- The biosynthesis of acetovanillone in tobacco cell-suspension cultures
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A soluble enzyme, extracted from tobacco cell-suspension cultures 24 h after treatment with 100 μM methyl jasmonate, has been shown to synthesize acetovanillone (apocynin) from feruloyl-CoA in the presence of NAD. The enzyme displayed Michaelis-Menten kinetics with apparent Km values of 5.6 μM for feruloyl-CoA and 260 μM for NAD and exhibited very high specificity for its substrates. The increase in acetovanillone synthase activity was followed by an increase in the concentration of both acetovanillone and acetosyringone in the culture medium. No intermediate could be detected when analysing the reaction medium by HPLC during the formation of acetovanillone in cell-free extracts. The apparent molecular mass estimated by gel permeation on an FPLC column was ca. 79 kDa. To our knowledge, this is the first report of an enzymic system catalysing the synthesis of an acetophenone. This work demonstrates that the biosynthesis of acetophenones in tobacco proceeds from hydroxycinnamic acids through a CoA-dependent β-oxidation pathway. Interestingly in methyl jasmonate-treated cells, which synthesize very large amounts of hydroxycinnamoylputrescines, inhibition of the synthesis of these conjugates increased the concentration of acetovanillone and acetosyringone in the culture medium, suggesting that the two metabolic pathways can compete for their common precursors, i.e. hydroxycinnamoyl-CoA thioesters.
- Negrel, Jonathan,Javelle, Francine
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Read Online
- Catalytic C(β)-O Bond Cleavage of Lignin in a One-Step Reaction Enabled by a Spin-Center Shift
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A challenge to the utilization of lignin as a feedstock for aromatic fine chemicals lies in selective cleavage of copious β-O-4 linkages. A photocatalytic strategy for the selective cleavage of the C(β)-O bonds of model substrates and natural lignin extracts is achieved by a redox-neutral, catalytic cycle that does not require stoichiometric reagents. Mechanistic studies reveal the generation of a thiyl radical, which is derived from a cystine-derived H-atom transfer catalyst, initiates a spin-center shift (SCS) that leads to C(β)-O bond cleavage. The SCS reactivity is reminiscent of the C(β)-O bond cleavage chemistry that occurs in the active site of ribonucleotide reductase.
- Zhu, Qilei,Nocera, Daniel G.
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p. 14181 - 14187
(2021/11/27)
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- Synthesis method of 1-(4-hydroxy-3,5-dimethoxyphenyl)ethan-1-one
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The invention relates to a synthesis method of 1-(4-hydroxy-3,5-dimethoxyphenyl)ethan-1-one. The synthesis method is characterized by comprising the following steps: removing a 2-methyl group from 1,2,3-trimethoxybenzene serving as an initial raw material to obtain 2,6-dimethoxyphenol; then carrying out a reaction on 2,6-dimethoxyphenol and an acetyl group to obtain 2,6-dimethoxyphenylacetate; andfinally, rearranging 2,6-dimethoxyphenol to obtain the 1-(4-hydroxy-3,5-dimethoxyphenyl)ethan-1-one. Compared with the prior art, the method adopts non-toxic and environment-friendly materials as rawmaterials, is simple to operate and mild in reaction, does not cause environmental pollution or harm to operators, and is suitable for large-scale production.
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Paragraph 0019; 0025-0027; 0028; 0032-0033; 0034; 0038-0039
(2020/05/30)
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- Profiling of the formation of lignin-derived monomers and dimers from: Eucalyptus alkali lignin
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Lignin is a renewable and the most abundant aromatic source that can be used for extensive chemicals and materials. Although approximately 50 million tons of lignin are produced annually as a by-product of the pulp and paper industry, it is currently underutilized. It is important to know the structural features of technical lignin when considering its application. In this work, we have demonstrated the formation of low-molecular-weight constituents from hardwood (Eucalyptus) lignin, which produces much more low-molecular-weight constituents than softwood (spruce) lignin, after a chemical pulping process, and analyzed the micromolecular compositions in the alkali lignin after fractionation by dichloromethane (DCM) extraction. By applying analytical methods (gel-permeation chromatography, 2D NMR and GC-MS) with the aid of evidence from authenticated compounds, a great treasure trove of lignin-derived phenolic compounds from Eucalyptus alkali lignin were disclosed. Except for some common monomeric products, as many as 15 new lignin-derived monomers and dimers including syringaglycerol, diarylmethane, 1,2-diarylethanes, 1,2-diarylethenes, (arylvinyl ether)-linked arylglycerol dimers and isomeric syringaresinols were identified in the DCM-soluble fraction. Regarding the formation and evolution of the Cα-condensed β-aryl ether structure, a novel route that is potentially responsible for the high content of β-1 diarylethenes and diarylethanes in the lignin low-molecular-weight fraction, in addition to the β-1 (spirodienone) pathway, was proposed. This work not only provides novel insights into the chemical transformation of S-G lignin during the alkali pulping process, but also discovered lignin-derived phenolic monomers and dimers that can potentially be used as raw materials in the chemical or pharmaceutical industries. This journal is
- Hu, Zhenhua,Li, Suxiang,Lu, Fachuang,Shi, Lanlan,Wang, Chen,Yue, Fengxia,Zhang, Han,Zhao, Chengke
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supporting information
p. 7366 - 7375
(2020/11/18)
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- Structural features and antioxidant activities of Chinese quince (Chaenomeles sinensis) fruits lignin during auto-catalyzed ethanol organosolv pretreatment
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Chinese quince fruits (Chaenomeles sinensis) have an abundance of lignins with antioxidant activities. To facilitate the utilization of Chinese quince fruits, lignin was isolated from it by auto-catalyzed ethanol organosolv pretreatment. The effects of three processing conditions (temperature, time, and ethanol concentration) on yield, structural features and antioxidant activities of the auto-catalyzed ethanol organosolv lignin samples were assessed individually. Results showed the pretreatment temperature was the most significant factor; it affected the molecular weight, S/G ratio, number of β-O-4′ linkages, thermal stability, and antioxidant activities of lignin samples. According to the GPC analyses, the molecular weight of lignin samples had a negative correlation with pretreatment temperature. 2D-HSQC NMR and Py-GC/MS results revealed that the S/G ratios of lignin samples increased with temperature, while total phenolic hydroxyl content of lignin samples decreased. The structural characterization clearly indicated that the various pretreatment conditions affected the structures of organosolv lignin, which further resulted in differences in the antioxidant activities of the lignin samples. These results can be helpful for controlling and optimizing delignification during auto-catalyzed ethanol organosolv pretreatment, and they provide theoretical support for the potential applications of Chinese quince fruits lignin as a natural antioxidant in the food industry.
- Cheng, Xi-Chuang,Guo, Xin-Ran,Liu, Hua-Min,Liu, Yu-Lan,Qin, Zhao,Wang, Xue-De
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p. 4348 - 4358
(2020/09/22)
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- Synthesis of CoFeO mixed oxides via an alginate gelation process as efficient heterogeneous catalysts for lignin depolymerization in water
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A catalytic oxidative fragmentation of a lignin dimer and polymer extracted from wheat straw was successfully performed under eco-friendly conditions: 10% O2/N2 as the oxidizing agent, water as the solvent (pH ≈ 7), and Co3O4, Fe2O3 and CoFeO mixed oxides as heterogeneous catalysts and at temperatures of T = 150 °C and 200 °C. These catalysts unexpectedly showed tunable selectivity that directly depends on the composition of the selected bimetallic nanoparticles. High selectivity for benzoic acid and alkylbenzene (above 50%) was observed over Co50-Fe50 at 200 °C. Under similar conditions, the conversion of wheat organosolv lignin over Co50-Fe50 at 150 °C for 4 h yielded up to 50 wt% of monomeric species (based on dry lignin) and up to 19% of aromatic molecules with high selectivity to aromatic aldehydes (syringaldehyde and vanillin), up to 60%. An important fraction of water-soluble oligomers, with low molecular weights, was also formed during the catalytic treatment. The oxide nanomaterials were readily separated from the residual lignin during the recyclability test. The yield and the product distribution can be tuned by choosing the oxidation parameters: temperature, reaction time, oxygen partial pressure, solvent and catalyst charges.
- Hdidou,Khallouk,Solhy,Manoun,Oukarroum,Barakat
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p. 5445 - 5453
(2018/11/20)
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- Electrochemical Lignin Degradation in Ionic Liquids on Ternary Mixed Metal Electrodes
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Lignin is the second most abundant natural polymer and a promissing feedstock for the generation of renewable aromatic chemicals. We present an fundamental approach for the electrocatalytic cleavage of lignin dissolved in a recoverable, inexpensive ionic liquid using mixed metal oxide electrodes of different compositions. The distribution of depolymerization products generated by electrochemical oxidation were analyzed by means of mass spectrometry. The distribution and yield of the cracked species was found to depended strongly on the implemented metal catalyst and therefore offers the potential to tailor the amount and composition of the low molecular weight cleavage products. This approach could help to provide a more sustainable valorization of lignin for the potential production of high value aromatic compounds due to synergistic effects.
- Rauber, Daniel,Dier, Tobias K.F.,Volmer, Dietrich A.,Hempelmann, Rolf
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p. 189 - 208
(2017/12/18)
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- Method forsynthesizing ketone by oxidation of alkene under catalysis of iron
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The invention discloses a method for synthesizing ketoneby oxidation of alkene under catalysis of iron, and belongs to the field of catalyzed synthesis technologies and fine chemical synthesis. According to the specific method, air or oxygen is taken as an oxidizing agent under the acceleration action ofhydrosilaneand a ketone compound is synthesized byoxidation of alkene under catalysis of iron. The method has the advantages that the catalyst is wide in source, cheap and environment-friendly; the oxidant is wide in source and cheap and does not generate a waste; the reaction conditions are mild, the selectivity is high and the yield is high;a substrate is wide and stable; a functional group of the substrate is good in compatibility and the application range of the substrate is wide; and alkene molecules can be well converted into the ketone. The separation yield of a target product reaches 98% under the optimized reaction conditions.
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Paragraph 0154; 0155; 0156
(2017/07/23)
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- Method for selective demethylation of ortho-trimethoxybenzene compounds
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The invention relates to a method for selective demethylation of ortho-trimethoxybenzene compounds and provides a method for preparation of 2,6-dimethoxyphenol derivatives by selective demethylation of ortho-trimethoxybenzene in different substitution types. By taking substitutional or non-substitutional ortho-trimethoxybenzene as a raw material, taking ZrCl4 as a catalyst and taking anisole as an additive, a ratio of the raw material to the catalyst to the additive is optimized in a reaction process to realize selective demethylation at a low reaction temperature ranging from the room temperature to 60 DEG C. The method has the advantages of mild reaction conditions, safety, reliability, low cost and easiness in operation and acquisition of the additive and the catalyst for reaction, simplicity and easiness in separation of reaction products, wide substrate application range and the like. The method effectively improves reaction safety and controllability and has an extensive application prospect in preparation of medicines, material intermediates and fine chemicals.
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Page/Page column 5
(2017/04/03)
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- Catalytic oxidation of lignin-acetoderivatives: A potential new recovery route for value-added aromatic aldehydes from acetoderivatives
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Catalytic wet air oxidation (CWAO) of lignin and phenolic composition of wastewater is a useful pathway towards the recovery of valuable compounds. In this study, bamboo lignin was catalytically oxidized to aromatic aldehydes and acetoderivatives; similarly acetovanillone and acetosyringone were oxidized to vanillin and syringaldehyde, respectively. A total product yield of 9.5% from bamboo lignin and a vanillin yield of 51% with greater than 90% selectivity from acetovanillone were achieved. The proposed reaction pathways suggest a two-step route towards the formation of value-added aromatic aldehydes from lignin via degradation of acetoderivatives. The kinetics study for the degradation of acetovanillone and formation of vanillin was reported for the first time in the temperature range of 120-150°C, with activation energies of 85.29 kJ mol-1 and 120.7 kJ mol-1, respectively. To date, CWAO breaks down the lignin polymer and toxic phenolic compounds reasonably and effectively, producing value-added aldehydes, which could become a potential new route for the recovery of value-added products.
- Alunga, Kissa R.,Ye, Yue-Yuan,Li, Shui-Rong,Wang, Duo,Liu, Yun-Quan
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p. 3746 - 3753
(2015/06/30)
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- Cu(OAc)2-catalyzed remote benzylic C(sp3)-H oxyfunctionalization for C=O formation directed by the hindered para-hydroxyl group with ambient air as the terminal oxidant under ligand- and additive-free conditions
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A hindered para-hydroxyl group-directed remote benzylic C(sp3)-H oxyfunctionalization has been developed for the straightforward transformation of 2,6-disubstituted 4-cresols, 4-alkylphenols, 4-hydroxybenzyl alcohols and 4-hydroxybenzyl alkyl ethers into various aromatic carbonyl compounds. The ligand- and additive-free Cu(OAc)2-catalyzed atmospheric oxidation mediated by ethylene glycol unlocks a facile, atom-economical, and environmentally benign C=O formation for the functionalization of primary and secondary benzyl groups. Due to the pharmaceutical importance of 4-hydroxybenzaldehydes and 4-hydroxyphenones, the methodology is expected to be of significant value for both fundamental research and practical applications.
- Jiang, Jian-An,Chen, Cheng,Huang, Jian-Gang,Liu, Hong-Wei,Cao, Song,Ji, Ya-Fei
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supporting information
p. 1248 - 1254
(2014/03/21)
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- Inverse electron demand hetero-Diels-Alder reaction in preparing 1,4-benzodioxin from o-quinone and enamine
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A process for synthesizing 1,4-benzodioxin, through oxidation of a phenol to an o-quinone followed by treatment with an enamine, has been developed. Adduct stereochemistry is found to be retained via this one-pot reaction. The method uses hypervalent iodine reagent under mild conditions and is compatible with a wide scope of phenols and enamines.
- Zhang, Jinsong,Taylor, Chris,Bowman, Erich,Savage-Low, Leo,Lodewyk, Michael W.,Hanne, Larry,Wu, Guang
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p. 6298 - 6302
(2013/11/06)
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- DEPOLYMERIZATION OF LIGNIN USING SOLID ACID CATALYSTS
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The invention provides for a process for the depolymerization of lignin in an inert atmosphere to result in substituted phenolic monomer compounds. The process is catalysed by heterogeneous solid acid catalysts and is carried out in batch or continuous mode.
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Page/Page column 6; 7
(2012/12/13)
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- Selective demethylation and debenzylation of aryl ethers by magnesium iodide under solvent-free conditions and its application to the total synthesis of natural products
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An efficient selective demethylation and debenzylation method for aryl methyl/benzyl ethers using magnesium iodide under solvent-free conditions has been developed and applied to the synthesis of natural flavone and biphenyl glycosides. A variety of functional groups including glycoside were tolerated under the reaction conditions. Experimental results indicated that the removal of an O-benzyl group was easier than that of an O-methyl group, regardless of wherever they were meta or para to the carbonyl. Thus selective debenzylation can be achieved for substrates bearing both benzyloxy and methoxy groups.
- Bao, Kai,Fan, Aixue,Dai, Yi,Zhang, Liang,Zhang, Weige,Cheng, Maosheng,Yao, Xinsheng
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scheme or table
p. 5084 - 5090
(2010/04/03)
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- Microwave-assisted cleavage of aryl methyl ethers with lithium thioethoxide (LiSEt)
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Lithium thioethoxide (LiSEt), a white solid easily prepared from EtSH and n-BuLi in hexane, was identified as a highly efficient reagent for the cleavage (O-demethylation) of aryl methyl ethers, i.e. methyl-protected phenols. Of particular synthetic value are applications in the double deprotection of 1,2-dimethoxyarenes (to give catechols) and in the selective monodeprotection of di- and trimethoxyarenes. The thermal reactions, which are usually performed in DMF as a solvent, can be greatly accelerated through microwave irradiation. In this case, the monodemethylated products are usually formed in high (80-99%) yield within only 15 minutes.
- Cvengro?, Ján,Neufeind, Stefan,Becker, Anne,Schmalz, Hans-Günther
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experimental part
p. 1993 - 1998
(2009/04/07)
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- High-yielding cleavage of (aryloxy)acetates
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A reliable and high-yielding one-pot sequence for the removal of O-carboxymethyl moieties from phenols is presented. When diethylphosphoryl azide is employed as the azide transfer reagent in the Curtius rearrangement and glycerol in the subsequent hydrolytic workup, the protocol can be reliably applied to a very broad scope of substrates. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Spurg, Anke,Waldvogel, Siegfried R.
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p. 337 - 342
(2008/09/18)
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- Synthesis of methoxy-substituted phenols by peracid oxidation of the aromatic ring
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A novel benign protocol for the preparation of hydroxy-methoxybenzene derivatives is disclosed. By utilizing this protocol, activated aromatic compounds such as l,3-dimethoxy-2-methyl-benzene and 1-(2,6-dimethoxyphenyl) ethanone are smoothly converted to the corresponding monohydroxylated compound. The reaction can be considered to be a normal aromatic electrophilic substitution reaction, and the regioselectivity for the reaction thus follows the similar rules as for electrophilic substitutions. The protocol is composed by benign reagents, namely, hydogenperoxide, acetic acid, and p-toluene sulfonic acid, which lead to the production of ethaneperoxoic acid in situ. The ethaneperoxoic acid operates as the hydroxylating reagent. The hydroxylation reaction is completed within a short period and requires moreover only mild experimental conditions, which make this novel protocol a green, cheap, and rapid process leading to hydroxy-methoxybenzene derivatives. The proposed reaction mechanism is supported by density functional theory and NMR spectroscopy experiments. The mechanism is constituted by two discrete steps: (a) addition of OH+ to the most nucleophilic carbon atom of the aromatic ring, which is the rate-determining step, and (b) the loss of the proton from the aromatic ring.
- Bjorsvik, Hans-Rene,Occhipinti, Giovanni,Gambarotti, Cristian,Cerasino, Leonardo,Jensen, Vidar R.
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p. 7290 - 7296
(2007/10/03)
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- Bismuth(III) triflate: Novel and efficient catalyst for Claisen and Fries rearrangements of allyl ethers and phenyl esters
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Bismuth(III) triflate catalyzed Claisen and Fries rearrangements of allyl phenyl ethers and phenyl acetates have been presented. The reaction proceeds smoothly and yields corresponding rearranged products in good yields. The bismuth triflate displays higher activity over the corresponding La, Yb, and Sc triflates.
- Sreedhar,Swapna,Sridhar
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p. 1433 - 1440
(2007/10/03)
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- Methoxyphenols from burning of Scandinavian forest plant materials
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Semivolatile compounds in smoke from gram-scale incomplete burning of plant materials were assessed by gas chromatography and mass spectrometry. Gas syringe sampling was shown to be adequate by comparison with adsorbent sampling. Methoxyphenols as well as 1,6-anhydroglucose were released in amounts as large as 10 mg kg-1 of dry biomass at 90% combustion efficiency. Wood, twigs, bark and needles from the conifers Norway spruce and Scots pine emitted 12 reported 2-methoxyphenols in similar proportions. Grass, heather and birchwood released the same 2-methoxyphenols but also the corresponding 2,6-dimethoxyphenols which are characteristic of angiosperms. The methoxyphenols are formed from lignin and differ in structure by the group in para position relative to the phenolic OH group. Prominent phenols were those with trans-l-propenyl and ethenyl groups in that position. Vanillin, 4- hydroxy-3-methoxybenzaldehyde, was a prominent carbonyl compound from the conifer materials. (C) 2000 Elsevier Science Ltd.
- Kjaellstrand, Jennica,Ramnaes, Olle,Petersson, Goeran
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p. 735 - 741
(2007/10/03)
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- New Phototriggers: Extending the p-Hydroxyphenacyl π-π* Absorption Range
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(Matrix Presented) Introducing 3-methoxy or 3,5-dimethoxy substituents on the 4-hydroxyphenacyl (pHP) photoremovable protecting group has been explored with two excitatory γ-amino acids, L-glutamic acid and γ-amino butyric acid (GABA). These substituents significantly extend the absorption range of the pHP chromophore, e.g., the tail of absorption bands of 2a,b extend above 400 nm, well beyond the absorptions of aromatic amino acids and nucleotides. Irradiation releases the amino acids with rate constants of ～107 s-1 and appearance efficiencies (Φapp) of 0.03-0.04. The photoproducts are formed through the pHP excited triplet and are primarily products of photoreduction and photohydrolysis. 1a,b also rearranged to the phenylacetic acid 3.
- Conrad II, Peter G.,Givens, Richard S.,Weber, J?rg F. W.,Kandler, Karl
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p. 1545 - 1547
(2007/10/03)
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- Studies of a novel biomimetic radical spirocyclisation
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The mechanism of the radical spirocyclisation 7→9 has been investigated. It has been shown by isotopic labelling that the biaryl ether oxygen does not emerge as the carbonyl group oxygen in the product, nor does the latter arise by hydrolysis of an intermediate e.g. 33 by added water. The mechanism of Scheme 1 path a is proposed, involving oxygen transfer from an aromatic nitro group to carbon in a cyclohexadienyl radical. Radical decarboxylation of the biarylamine derivative 29 does not lead to spirodienone 9 but diverts instead to the azathiaacetal 30.
- Topiwala, Upendra P.,Luszniak, Mark C.,Whiting, Donald A.
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p. 1185 - 1191
(2007/10/03)
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- Cobalt-Schiff Base Complex Catalyzed Oxidation of Para-Substituted Phenolics. Preparation of Benzoquinones
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Para-substituted phenolics, serving as models for lignin (a renewable source of carbon), are oxidized to the corresponding benzoquinone with oxygen in the presence of catalytic amounts of Co-Schiff base complexes.The reaction products observed depend on the structure of the catalyst.The 5-coordinate catalysts (pyridine)cobalt and amine>cobalt convert syringyl alcohol (3,5-dimethoxy-4-hydroxybenzyl alcohol) to 2,6-dimethoxybenzoquinone in high yield.In contrast, syringaldehyde (3,5-dimethoxy-4-hydroxybenzaldehyde) is unreactive toward these catalysts.However, the 4-coordinate Co(salen) converts syringaldehyde to 2,6-dimethoxybenzoquinone in 72percent isolated yield.Phenols bearing a single methoxy group on the ring are unreactive toward any catalyst in MeOH.However, vanillyl alcohol (3-methoxy-4-hydroxybenzyl alcohol) is converted to 2-methoxybenzoquinone with Co(N-Me salpr) and oxygen in 43percent yield in CH2Cl2, and 58percent yield in CH2Cl2 in the presence of 1percent CuCl2.The success of the oxidations appears to be related to the ease of removal of the phenolic hydrogen by the Co/O2 complex.Competitive deactivation of the catalyst occurs with substrates of lower reactivity.
- Bozell, Joseph J.,Hames, Bonnie R.,Dimmel, Donald R.
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p. 2398 - 2404
(2007/10/02)
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- Mechanism of a Novel Spirocyclisation Reaction; Intramolecular Oxygen Transfer to Carbon Radicals by Nitro Groups
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A mechanism for the novel radical spirocyclisation reaction 1 -> 2 is proposed, and is shown by isotopic labelling to involve transfer of oxygen from an aromatic nitro function to carbon in a cyclohexadienyl radical.
- Topiwala, Upendra P.,Whiting, Donald A.
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p. 2443 - 2444
(2007/10/02)
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- SELECTIVE DEACETYLATION OF AROMATIC ACETATES BY AMINOLYSIS
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Pyrrolidine was shown to deacetylate aromatic acetyl groups considerably faster than aliphatic groups.
- Mansson, Per
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p. 1845 - 1846
(2007/10/02)
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