Acceptor-dependent stereoselective glycosylation: 2'-CB glycoside-mediated direct beta-D-arabinofuranosylation and efficient synthesis of the octaarabinofuranoside in mycobacterial cell wall

[reaction: see text]. A reliable and generally applicable direct method for the stereoselective beta-arabinofuranosylation employing a 2'-carboxybenzyl arabinofuranoside as the glycosyl donor has been established. The acyl-protective group on glycosyl acceptors is essential for the beta-stereoselectivity. The power of the present acceptor-dependent glycosylation method was demonstrated by the efficient synthesis of the octaarabinofuranoside in arabinogalactan and lipoarabinomannan found in mycobacterial cell wall.