This paper describes a mild and efficient catalytic deprotection method for isopropylidene ketals and benzylidene acetals using AcOH/HO/DME(1,2-Dimethoxyethane). The method effectively removes ketal and acetal protecting groups from 2-deoxyglycosides which are prone to hydrolysis under acidic conditions. Moreover, it enables the selective removal of the terminal ketal over an internal one.
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http://dx.doi.org/10.1016/j.carres.2024.109167 | DOI Listing |
Food Chem
January 2025
Zhengzhou Tobacco Research Institute of CNTC, Zhengzhou, Henan 450001, China.
Flavors contain active aldehydes and ketones that react with glycerol and propylene glycol to form acetals and ketals. The identification of acetals and ketals is challenging due to the incomplete information in mass spectral libraries. This study examines the reaction kinetics of 36 aldehydes and ketones with propylene glycol and glycerol, and establishes a high sensitivity and throughput screening method for 185 acetals and ketals using GC-Orbitrap-MS.
View Article and Find Full Text PDFCarbohydr Res
July 2024
School of Chemistry Engineering, Sichuan University of Science & Engineering, Zigong, 643000, China. Electronic address:
This paper describes a mild and efficient catalytic deprotection method for isopropylidene ketals and benzylidene acetals using AcOH/HO/DME(1,2-Dimethoxyethane). The method effectively removes ketal and acetal protecting groups from 2-deoxyglycosides which are prone to hydrolysis under acidic conditions. Moreover, it enables the selective removal of the terminal ketal over an internal one.
View Article and Find Full Text PDFMacromol Rapid Commun
December 2022
Department of Chemistry, Johannes Gutenberg University Mainz, 55099, Mainz, Germany.
End group functionality is a key parameter of functional polymer chains. The end-capping efficiency of living polystyryl lithium with various epoxides, namely ethylene oxide (EO), ethoxy ethyl glycidyl ether (EEGE) and isopropylidene glyceryl glycidyl ether (IGG), is investigated with solvent gradient interaction chromatography (SGIC). Generally, end-capping efficiencies >95% are observed.
View Article and Find Full Text PDFFront Chem
August 2021
Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
1,2:3,5-Di-O-isopropylidene-α-D-xylofuranose (DX) is a major component of a new bio-crude: a viscous oil presenting petroleum-friendly properties produced by the ketalization of sugarcane bagasse. This article studies DX HDO (hydrodeoxygenation) over a Pd/HBEA catalyst in a batch reactor at 250°C The effects of hydrogen pressure from 10 to 40 bar, catalyst/DX ratio from ½ to 2, and reaction time 0-24 h were investigated. A range of conditions for complete hydrodeoxygenated DX into alkanes with a Pd/HBEA catalyst was found.
View Article and Find Full Text PDFMolecules
April 2020
A.V. Topchiev Institute of Petrochemical Synthesis, Russian Academy of Sciences (TIPS RAS), 29 Leninsky prospect, 119991 Moscow, Russia.
In this study approaches for chemical conversions of the renewable compounds 1,2-propanediol (1,2-PD) and 2,3-butanediol (2,3-BD) that yield the corresponding cyclic ketals and glycol ethers have been investigated experimentally. The characterization of the obtained products as potential green solvents and gasoline components is discussed. Cyclic ketals have been obtained by the direct reaction of the diols with lower aliphatic ketones (1,2-PD + acetone → 2,2,4-trimethyl-1,3-dioxolane (TMD) and 2,3-BD + butanone-2 → 2-ethyl-2,4,5-trimethyl-1,3-dioxolane (ETMD)), for which the Δ, Δ and Δ values have been estimated experimentally.
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