Elsevier, Tetrahedron Letters, 9(54), p. 1137-1140, 2013
DOI: 10.1016/j.tetlet.2012.12.048
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Dipyrranes bearing peracetylated mono- or disaccharidic C-1-deoxyalditol moieties were prepared from d-galactose, d-glucose, d-mannose, and lactose. A partially hydrolyzed polysaccharide (agarose) was also used as starting material for the synthesis of a disaccharide-containing C-glycoside dipyrrane. These compounds were synthesized as follows: the sugar starting materials were first submitted to a mercaptolysis–acetylation one-pot procedure (EtSH/HCl–Ac2O/pyridine). The resulting peracetylated diethyl dithioacetals were converted into dipyrranes through carbonyl deprotection (H5IO6, THF–Et2O) followed by TFA-catalyzed pyrrole condensation with yields up to 62%. Overall yields from sugar starting materials were up to 49%.