Methyl 1,2,3,4-tetra-O-acetyl-α-L-iduronate was prepared from methyl 1,2,3,4-tetra-O-β-D-glucuronate in two steps: Ferrier's photobromination and subsequent radical reduction with tris(trimethylsilyl)silane. The obtained methyl 1,2,3,4-tetra-O-acetyl-α-L-iduronate was a good glycosyl donor for the L-iduronidation when bis(trifluoromethanesulfonic)imide was employed as the activator. The reaction afforded the α-isomer as the major product, the configuration of which is the same as that of the L-iduronic acid unit in heparin and heparan sulfate.
Keywords: L-iduronic acid; L-iduronidation; bis(trifluoromethanesulfonic) imide; α-L-iduronide.