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Aqueous-Phase Reforming and BioForming Process
Published in Yatish T. Shah, Water for Energy and Fuel Production, 2014
Blommel and Cortright [15,60–63,66,67,87–89] pointed out that this transformation requires numerous types of condensation reactions such as (1) aldol condensation to form beta-hydroxy ketone and aldehydes; (2) dehydration of these products to form enone; (3) hydrogenation of conjugated enone to ketone, aldehyde, or alcohol; and finally (4) dehydration/hydrogenation or hydrogenolysis to form alkanes. This multifunctional process allows the formation of longer chain and branched hydrocarbons needed to produce gasoline, diesel, and jet fuels with subsequent distillation [15,60–64,66,67,78,87–89,98]. Many oxygenates such as alcohols, carbonyls, and acids can form C–C bonds through aldol and decarboxylative condensation reactions [15,64,78,98]. Further analysis and details on various types of condensation reactions and the role of different catalysts are given by Blommel and Cortright [15] along with some other published reports [60–63,66,67,87–89]. Currently, Virent Inc. is building a pilot plant to demonstrate the viability of the BioForming process at a larger scale with the aim of making a commercial process.
Task-Specific Ionic Liquids
Published in Pedro Lozano, Sustainable Catalysis in Ionic Liquids, 2018
21a-Catalyzed Claisen–Schmidt reaction between various ketones and aldehydes exhibited desirable results under softer reaction conditions. Initially, 21a was applied to the aldol condensation reaction of 4-nitro benzaldehyde with acetone with 30 mol% of 21a in dimethyl sulfoxide at 25°C. Instead of β-hydroxy ketone, it gave dehydration product, α,β-unsaturated ketone with (E)-configuration in excellent yield, Scheme 1.21. The results proved the catalytic capacity of 21a for convenient synthesis of the α,β-unsaturated ketone.
Carbohydrates and Nucleic Acids
Published in Michael B. Smith, A Q&A Approach to Organic Chemistry, 2020
As with other oxidizing tests, the Tollen’s test indicates the presence of an aldehyde or an α-hydroxy ketone. What is an osazone?
The keto–enol equilibrium and thermal conversion kinetics of 2- and 4-hydroxyacetophenone in the gas phase: a DFT study
Published in Molecular Physics, 2018
Yeljair Monascal, Eliana Gallardo, Loriett Cartaya, Alexis Maldonado, Yenner Bentarcurt, Gabriel Chuchani
Aromatic hydroxy ketones are an important class of compounds with several applications in the chemical industry. The 2-hydroxyacetophenone (2-HAP) and 4-hydroxyacetophenone (4-HAP) are used for the manufacture of aspirin and paracetamol, respectively [1,2]. 2-HAP is also an intermediate for the synthesis of flavonoids, coumarins and quinones including natural and biologically active compounds in high yields [3,4]. Both substrates may undergo a tautomeric equilibrium between the keto and enol forms (Scheme 1). At present, there is little information on gas-phase elimination reactions of this type of organic compounds.