Unprecedented β-manno type thiodisaccharides with a C-glycosylic function by photoinitiated hydrothiolation of 1-C-substituted glycals

Free-radical hydrothiolation of O -peracylated 1-C-(carbamoyl-, methoxycarbonyl- and cyano) substituted glycals with a range of sugar derived thiols gave the corresponding β- manno type 3-deoxy-3- S -disaccharides with full regio- and stereoselectivity. The configuration of the glycals ( arabino vs. lyxo ) and the size of the protecting groups had no significant effect on the outcome of the transformations. Formation of by-products was tracked down by LCMS studies and correlated with the electron density of the double bonds to show that the reactions were synthetically useful with a COOMe and especially with a CONH 2 group as the 1-C-substituent.