Magnesium(II)-coordinated Claisen rearrangement: a direct approach towards ulosonic acid derivatives

Unprecedented magnesium dihalide-catalysed Claisen rearrangement of 2-alkoxycarbonyl allyl vinyl ethers derived from α-chloroglycidic esters is reported in the glucidic series. A first application of this reaction concerns the stereoselective construction of a disaccharide analogue including a galactosyl and an ulosonic isopropyl ester moieties.