Electrochemical Bromination of Glycals

Herein, the convenient one-step electrochemical bromination of glycals using Bu4NBr as the brominating source under metal-catalyst-free and oxidant-free reaction conditions was described. A series of 2-bromoglycals bearing different electron-withdrawing or electron-donating protective groups were successfully synthesized in moderate to excellent yields. The coupling of tri-O-benzyl-2-bromogalactal with phenylacetylene, potassium phenyltrifluoroborate, or a 6-OH acceptor was achieved to afford 2C-branched carbohydrates and disaccharides via Sonogashira coupling, Suzuki coupling, and Ferrier rearrangement reactions with high efficiency. The radical trapping and cyclic voltammetry experiments indicated that bromine radicals may be involved in the reaction process.

Antimicrobial and anticancer activities of copolymers of tri-O-acetyl-D-glucal and itaconic anhydride

This paper reports the synthesis and characterization of monomers itaconic anhydride (IA) and tri-O-acetyl-D-glucal (TAG) as well as 4,6-di-O-acetyl-D-glucal (PSG). The homopolymers and copolymers of IA and TAG were synthesized via free radical copolymerization in bulk using azobisiso-butyronitrile as an initiator using different feed ratios of monomers. Their structural, molecular, and thermal characterization was done using 1H-NMR spectroscopy, gel permeation chromatography, and differential scanning calorimetry, respectively. The glass transition temperature (Tg) of copolymers was found in the range of 139-145 ?C. The highest Tg was found for IA-TAG2 copolymers, whereas IA-TAG4 copolymer showed lowest Tg. The molecular weight of the copolymers was in the range 5157-5499 g mol-1. The monomer TAG undergoes Ferrier rearrangement in water to give PSG. The antimicrobial activity of IA, TAG, PSG and IA-TAG copolymers was studied using the minimum microbicidal concentration-broth dilution method. TAG, IA, and PSG, as well as homopolymer and copolymers of IA and TAG are excellent antimicrobial agents.

New Insights into the Reactivity of 2-Halo-Glycals. Synthesis of Novel Iodinated Oand S-Glycosides

<p><i>This is the first report on the Ferrier rearrangement of 2-halo-glycals with S-nucleophiles. We present herein the selective synthesis of new 2-iodo-2,3-unsaturated O- and S-glycosides. We obtained in good yields and high anomeric selectivity </i><i>a</i><i>-glycosydes. As a particular behaviour, we also describe heteroaromatic thio sugar derivatives were the C3 addition was performed in an alternative mechanism. A complete structure and conformation analysis by NMR was also presented. </i></p>

New Insights into the Reactivity of 2-Halo-Glycals. Synthesis of Novel Iodinated Oand S-Glycosides

<p><i>This is the first report on the Ferrier rearrangement of 2-halo-glycals with S-nucleophiles. We present herein the selective synthesis of new 2-iodo-2,3-unsaturated O- and S-glycosides. We obtained in good yields and high anomeric selectivity </i><i>a</i><i>-glycosydes. As a particular behaviour, we also describe heteroaromatic thio sugar derivatives were the C3 addition was performed in an alternative mechanism. A complete structure and conformation analysis by NMR was also presented. </i></p>