Synthesis of a β-GlcN-(1→4)-MurNAc building block en route to N-deacetylated peptidoglycan fragments
摘要:
Some bacteria present a variation in their peptidoglycan structure that is the absence of the N-acetyl substituent in the glucosamine residue. Very recently, this structural modification was demonstrated to be critical for host innate immune evasion in Listeria monocytogenes. To shed light on the molecular details of the evasion mechanism, the synthesis of some N-deacetylated peptidoglycan fragments is needed. En route to this goal a high-yielding synthesis of a GlcN-MurNAc disaccharide building block has been accomplished. A careful study of the optimal protecting groups and reaction conditions was done to have a complete beta-stereoselectivity in glycosylation as well as to ensure a high versatility to the disaccharide building block. (C) 2009 Elsevier Ltd. All rights reserved.
p-Methoxybenzyl-N-phenyl-2,2,2-trifluoroacetimidate: a versatile reagent for mild acid catalyzed etherification
摘要:
PMB-NPTFA la is a new month bench stable and powerful reagent for the formation of PMB ethers. Several alcohols were protected in high yields and short reaction times, using low reagent loading and small catalytic amounts of Bi(OTf)(3). The mild conditions of the reaction confer a good orthogonality to acid- and base-sensitive protecting groups. (C) 2013 Elsevier Ltd. All rights reserved.