Short synthetic sequence for 2-sulfation of alpha-L-iduronate glycosides.

Hunter syndrome (mucopolysaccharidosis-II) is caused by deficiency of the lysosomal enzyme iduronate-2-sulfatase. The assay of this sulfatase requires the use of alpha-L-iduronate glycosides containing a sulfate at the 2-position. We report a simple, three-step procedure for the introduction of sulfate at the 2-position starting with the methyl ester of alpha-L-iduronate glycosides. The procedure involves protection of the 2- and 4-hydroxyl groups of the iduronate moiety as the dibutyl stannylene acetal, selective sulfation with sulfur trioxide-trimethylamine, and deprotection of the methyl ester to afford the desired 2-sulfate in 61% overall yield.