Synthesis of the 3′-C-carboxymethyl Lewis X derivative: a novel selectin blocker

The 3′-C-carboxymethyl Lex derivative carrying the 2-(tetradecyl)hexadecyl residue was synthesized by employing 3′-C-carboxymethyl galactose as a key intermediate, which was prepared from the suitably protected galactose by Swern oxidation and Wittig-Horner carboxymethylenation, followed by stereoselective reduction of the double bond. The compound obtained showed much more potent activity as a selectin blocker than the sialyl Lex derivative with 2-(tetradecyl)hexadecyl residue.