Rapid synthesis of glycosyl bromides by ultrasound irradiation

Defining the Scope of the Acid‐Catalyzed Glycosidation of Glycosyl Bromides

“…The field has also seen advancement in the synthesis of glycosyl halides. For instance, per‐acetylated and per‐benzoylated bromides are commonly obtained from the corresponding glycosyl esters by reaction with HBr. Thioglycoside precursors can also be readily converted in the corresponding bromides by reaction with bromine .…”

Synthesis and Glycosidation of Anomeric Halides: Evolution from Early Studies to Modern Methods of the 21st Century

“…Kartha and Jennings reported a one-pot synthesis of per-acetylated glycosyl bromide wherein free sugars were first treated with acetic anhydride followed by the addition of HBr in AcOH . Another method for the synthesis of glycosyl bromides involves the treatment of free sugars with acetic anhydride in the presence of catalytic HClO 4 in acetic acid followed by bromination with AcBr-MeOH with or without sonication. , A reversal in the order of the reagent addition wherein sugar and acetic anhydride were added to a mixture of acetyl bromide and methanol in acetic acid also produced glycosyl bromides in excellent yields . Lin et al treated unprotected sugars with LiClO 4 -Ac 2 O followed by the reaction with HBr-AcOH .…”

“…Fischer and Helferich treated per-benzoylated glucose with a saturated a solution of HBr in glacial acetic acid . This method was further modified by Hudson and co-workers. , Another efficient method for the synthesis of benzoylated glycosyl bromides involves the treatment of per-benzoylated sugars with AcBr-MeOH using ultrasound irradiation . All the previous methods for the synthesis of glycosyl bromides from the corresponding 1- O -acyl derivatives rely on highly reactive, toxic, sensitive, and corrosive acids.…”

“…211,212 Another efficient method for the synthesis of benzoylated glycosyl bromides involves the treatment of per-benzoylated sugars with AcBr-MeOH using ultrasound irradiation. 198 All the previous methods for the synthesis of glycosyl bromides from the corresponding 1-O-acyl derivatives rely on highly reactive, toxic, sensitive, and corrosive acids. To address these issues, Tang and co-workers described a milder reaction conditions for an efficient synthesis of glycosyl bromides.…”