GLYCOSYLIMIDATES .54. SYNTHESIS OF THE GLCNAC-BETA(1-]4)MURNAC-BETA(1-]4)GLCNAC-BETA(1-]4)MURNAC TETRASACCHARIDE OF BACTERIAL PEPTIDOGLYCAN

From 2-azido-2-deoxy-D-glucose have been prepared at 1-O and/or 4-O selectively protected glucosamine and muramic acid derivatives, which were transformed into glycosyl donors 6 and 14a,b and into glycosyl acceptors 7 and 15. The reaction of these donors and acceptors yielded disaccharides 8 and 11-13. Selective 1a-O-deprotection of disaccharide 12 and subsequent treatment with trichloroacetonitrile afforded disaccharide donor 17; selective removal of the 4b-O-protective groups in disaccharides 8 and 11 furnished disaccharide acceptor 9. These building blocks were employed in the synthesis of beta-connected tetrasaccharide 18 which gave upon azido group reduction, acetylation of the amino groups, and complete O-deprotection the desired target molecule 1 characterized as its fully O-acetylated product 2.