Side reactions with 2,2,2-trichloroethoxysulfates during the synthesis of glycans

•Diols and triols were regioselectively 2,2,2-trichloroethoxysulfated.•Protected sulfates were tolerable in many types of reactions.•Side reactions occurred during 2,2,2-trichloroethoxysulfation at the primary alcohol.•Protected sulfates caused nucleophilic side reactions inter- and intramolecularly.

Protected sulfate groups may be used as an alternative tool to provide sulfate esters at hydroxyl and amino groups, particularly on complex glycans. We examined 2,2,2-trichloroethoxysulfation at the mono-, di-, and trihydroxyl groups of saccharide moieties to show regioselective sulfation. We found some side reactions including inter- and intramolecular nucleophilic reactions with 2,2,2-trichloroethoxysulfates.

Graphical abstractRegioselective 2,2,2-trichloroethoxysulfations at mono-, di-, and trihydroxyl groups on saccharide moieties were examined. We observed side reactions including inter- and intramolecular nucleophilic reactions in protected sulfations.Figure optionsDownload full-size imageDownload as PowerPoint slide