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2-Deoxy-glycosides, in which the C-2 hydroxyl group is replaced with a hydrogen atom, are important motifs in numerous bioactive natural products and pharmaceutical molecules. Herein, an improved dilauroyl peroxide-mediated radical deiodination reaction b

Described here is a selective synthesis of 2,3-dihydropyrrole-fused N-glycosides through rhodium-catalyzed denitrogenative transannulation of N-sulfonyl-1,2,3-triazoles with glycals. A series of pyrroline-fused N-glycosides are afforded in moderate to exc

A simple and efficient procedure was designed for the preparation of pyranoid glycals. In a novel fashion, a series of protected glycopyranosyl bromides underwent reductive elimination in the presence of zinc dust and ammonium chloride in CH3CN at 30-60 °C. The corresponding glycals were obtained with excellent isolated yields (72-96%) in a short time (20-50 min). Furthermore, the transformation was compatible with different protection patterns and conveniently scalable (86% for 45 g acetobromoglucose) which made it very applicable in organic synthesis.

A convenient and environmentally benign procedure for the synthesis of glycals from glycosyl bromides with very low zinc dust loading (1.5 equiv.) is described. The process is activated by β-cyclodextrin and ultrasound. Based on 19 samples, this method has been demonstrated to be highly effective for a broad range of glycosyl bromides, including acid- or base-sensitive and disaccharide glycosyl bromides. A yield of 85%-96% of glycals was obtained. Copyright

Glycals were synthesized via a simple, mild, convenient and environmentally benign procedure, in which protected glycosyl bromides undergo the reductive elimination in the presence of zinc in PEG-600/H2O at room temperature. The glycals were obtained in 75-92% isolated yields.

1,5-Anhydro-3,4,5-tri-O-benzoyl-2-deoxy-D-arabino-hex-1-enitol (1) was boiled under reflux with methanol and AG 50W-X8 cation-exchange resin.A two-product mixture of glycosides (2 and 3) was obtained in 38percent yield, together with 19percent of unreacted material. 1,5-Anhydro-3,6-di-O-benzoyl-2-deoxy-D-arabino-hex-1-enitol (7) was prepared from 1,5-anhydro-2-deoxy-D-arabino-hex-1-enitol by selective benzoylation, from wich the corresponding 4-methansulphonate 8 was obtained.Treatment of 8 with sodium benzoate in hexamethylphosphoric triamide for 72 h at 100 deg C afforded 1,5-anhydro-3,4,6-tri-O-benzoyl-2-deoxy-D-xylo-hex-1-enitol (9) in 52percent yield.An unknow byproduct (B), tentitatively shown to be a tri-O-benzoyl-D-hex-2-enopyranose analog, was also isolated in 14percent yield.The 270-MHz n.m.r. spectrum of B was analyzed in terms of its J1,3, J2,4 and J4,5 coupling constant in relation to the various configurational and conformational possibilities for hex-2-enopyranose, and was identified as 1,4,6-tri-O-benzoyl-2,3-dideoxy-α-D-threo-hex-2-enopyranose having the oH5 conformation.The analysis presented should also be applicable to pent-2-enopyranose systems.When 9 was treated with methanol in the presence of AG 50W-X8 cation-exchange resin, a mixture of glycosides 4 and 5 was obtained in 47percent yield.The low yields were attributed to methanolysis of the benzoyl groups during the reaction.