Thiomidoyl approach to the synthesis of α-sialosides

Novel sialosyl donors, S-benzoxazolyl (SBox) and S-thiazolyl (STaz) sialosides, have been synthesized and applied to the stereoselective synthesis of alpha-sialosides. It was also demonstrated that it is possible to selectively activate SBox sialyl donor over ethyl thioglycoside, allowing the direct synthesis of disaccharide donors that could be used in subsequent glycosylations without further manipulations. (C) 2004 Elsevier Ltd. All rights reserved.