1464-44-4Relevant articles and documents
Isotope studies of the transfer of the carbon atoms of carbohydrate derivatives into aromatic compounds (especially xanthene) under degradation conditions
Ferrier,Severn,Furneaux,Miller
, p. 87 - 94 (1992)
Treatment of various 13C-carbohydrate-labelled phenyl β-D-glucopyranosides at 350°C in aqueous phenol in the presence of zinc chloride, with 13C NMR analysis of the xanthene formed as the major neutral product, indicated that the methylene carbon atom (C-9) of this compound was derived from C-1 (30%), C-2 (20%), and C-6 (50%) of the glucosyl units. In addition, 4.5% of the carbon from the sugar was incorporated into the aromatic rings of the xanthene. Mass spectrometry of the phenol produced on heating methyl α-D-glucopyranoside (50% U-13C) at 350°C for 1 h in aqueous zinc chloride showed the aromatic rings to be derived from the glucosyl moiety, partly without cleavage of the carbon chain and also after cleavage and recombination of the fragments.
Phenyl glycosides – Solid-state NMR, X-ray diffraction and conformational analysis using genetic algorithm
Wa?ejko, Piotr,Bukowicki, Jaros?aw,Dobrzycki, ?ukasz,Socha, Pawe?,Paradowska, Katarzyna
, p. 126 - 136 (2019/01/03)
The X-ray structures of 2,6-dimethylphenyl and phenyl 2,3,4,6-tetra-O-acetyl β-glucosides (1 and 3) and phenyl α-mannoside (6) were obtained. The independent part of the unit cell of the glycosides 1 and 6 was formed by one molecule, and for the glucoside 3, two molecules in the crystal cell were observed. In deacetylated glycosides 4 and 6 the crystal structure was established by a hydrogen bond network formed between the sugar hydroxyls and solvent molecules. The 13C CPMAS NMR spectra of aryl glycosides 1–6 were analysed. In the spectrum of 3, doubling of the C4 aryl signal was observed which confirmed the presence of two independent molecules in the solid sample. The GAAGS (Genetic Algorithm-Assisted Grid Search) method was used to determine the low-energy conformers of α-mannosides and β-glucosides. The orientation of the aryl pendant group was calculated using Molecular Mechanics (MMFF94) as well as Quantum Mechanics theory (DFT, B3LYP/6-31 + G(d,p)).
A new look at acid catalyzed deacetylation of carbohydrates: A regioselective synthesis and reactivity of 2-O-acetyl aryl glycopyranosides
Stepanova, Elena V.,Nagornaya, Marina O.,Filimonov, Victor D.,Valiev, Rashid R.,Belyanin, Maxim L.,Drozdova, Anna K.,Cherepanov, Victor N.
, p. 60 - 66 (2018/02/20)
In the present work we report that acetyl groups of per – acetylated aryl glycosides have different reactivity during the acidic deacetylation using HCl/EtOH in CHCl3, which leads to preferential deacetylation at O-3, O-4 and O-6. Thereby, the one-step preparation of 2-O-acetyl aryl glycosides with simple aglycon was accomplished for the first time. It was proved that the found reagent is to be general and unique for the preparation of series of 2-О-acetyl aryl glycosides. We have determined the influence of both carbohydrate moiety and the aglycon on the selectivity of deacetylation reaction by kinetic experiments. Using DFT/B3LYP/6-31G(d,p) and semi-empirical АМ1 methods we have found that the highest activation barrier is for 2-О-acetyl group. This completely explains the least reactivity of 2-О-acetyl group.