Sulfur atom configuration of sulfinyl galactofuranosides determines different reactivities in glycosylation reactions

Sulfinyl β-d-galactofuranosides 3(R,S) and 9(R,S) were used as new hexofuranosyl donors in glycosylation reactions. Activation by trifluoromethanesulfonic anhydride involved different reaction pathways depending on the stereochemistry at the sulfur atom. Experimental results underlined a more suitable reactivity of 3(R) and 9(R) versus 3(S) and 9(S), respectively, for the synthesis of β-d-galactofuranosides.