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. Fullsize Image
1,2,3,4-四-O-乙酰基-α-
L-艾杜糖醛酸甲酯由 1,2,3,4-四-O -β-
D-葡萄糖醛酸甲酯分两步制备:费里尔光
溴化和随后的自由基用三(三甲基甲
硅烷基)
硅烷还原。当使用双(
三氟甲磺酸)
亚胺作为活化剂时,所获得的1,2,3,4-四-O-乙酰基-α-
L-艾杜糖醛酸甲酯是
L-艾杜糖醛酸化的良好糖基供体。反应主要产物为α-异构体,其构型与
肝素和
硫酸乙酰
肝素中
L-艾杜糖醛酸单元的构型相同。 全尺寸图像