SYNTHETIC STUDIES ON SELECTIN LIGANDS INHIBITORS - A SYSTEMATIC SYNTHESIS OF SULFATIDE AND ITS HIGHER CONGENERS CARRYING 2-(TETRADECYL)HEXADECYL GROUP AS A CERAMIDE SUBSTITUTE/

A systematic synthesis of sulfatide (I) and novel sulfatide analogs (I I-VI) carrying 2-(tetradecyl)hexadecyl group as a ceramide substitute is described. The 3-O-, 4-O- and 3,4-di-O-levulinoyl derivatives of ga lactopyranosyl trichloroacetimidates (1, 12, and 13) were coupled with -3-O-acetyl-2-octadecanamido-4-octadecene-1,3-diol or 2-(tetradecyl)h exadecan-1-ol. The resulting glycolipids (2, 4, 14, and 15) were each transformed, by selective removal of the levulinoyl group(s), and succ essive sulfation and de-O-acylation, into the 3-sulfates (I, II), 4-su lfate (III), and 3,4-disulfate (IV). The 6-sulfate (V) was prepared fr om 2-(tetradecyl)hexadecyl beta-D-galactopyranoside (21) via the 6-O-t -butyldimethylsilyl derivative, while the 3'-sulfate of 2-(tetradecyl) hexadecyl beta-D-lactoside (VI) was synthesized from 2-(trimethylsilyl )ethyl 3'-O-benzyl-beta-D-lactoside (26). The structures of the sulfat ed glycolipids (I-VI) were characterized by ion-spray MS, MS/MS, and H -1 NMR spectrometry.