Synthesis of vinyl glycosides and carbohydrate vinyl ethers from mixed acetals: a hetero-Diels-Alder approach to deoxygenated disaccharides

Treatment of mixed acetal glycosides as well as other types of carbohydrate mixed acetals with TMS-triflate and an amine base provides vinyl glycosides or carbohydrate vinyl ethers. Hetero-Diels-Alder reactions of carbohydrate 3-O- and 6-O-vinyl ethers with ethyl (E)-ethoxymethylenepyruvate were carried out as part of a model study for the synthesis of deoxygenated disaccharides of antibiotics.