Reactivity-based one-pot total synthesis of fucose GM1 oligosaccharide: a sialylated antigenic epitope of small-cell lung cancer.

The total synthesis of the sialic acid-containing antigenic epitope fucose GM(1) (Fuc-GM(1)) by an improved reactivity-based one-pot synthetic strategy is reported. Based on a thioglycoside reactivity database, three saccharide building blocks, 3, 4, and 5, were designed and prepared to incorporate a descending order of reactivity toward thiophilic activation. Using the reactivity-based one-pot synthetic method, the fully protected Fuc-GM(1) glycoside 2 was furnished in a facile manner, which was globally deprotected to give the Fuc-GM(1) glycoside 1. In addition, using the promoter system 1-(benzensulfinyl)piperidinetrifluoromethanesulfonic anhydride, the product yield was improved and the reaction time was reduced in comparison with the N-iodosuccinimidetrifluoromethanesulfonic acid- and dimethyl (thiomethyl) sulfonium trifluoromethanesulfonate-promoted systems.