Free-radical hydrothiolation of glycals: a thiol-ene-based synthesis of S-disaccharides

A method for the synthesis of a new family of 1-deoxy S-disaccharides has been established via free-radical hydrothiolation of glycals by sugar thiols (thiol-ene coupling). The photoinduced coupling between four tri-O-acetyl-D-glycals and three different sugar thiols reveals that the reaction efficiency and stereoselectivity are highly dependent on the stereochemistry of the OAc groups at C3 and C4 of the glycal. (C) 2011 Elsevier Ltd. All rights reserved.