Synthesis of Urea-Tethered Neoglycoconjugates and Pseudooligosaccharides in Water

Abstract

A novel approach to the synthesis of urea glycosides in aqueous media has been explored. Steyermark's glucopyranosyl oxazolidinone was found to be a good synthon for anchoring glucosyl moieties onto amines and thiols. The present method was successfully applied to establish a new route for the synthesis of urea-tethered neoglycoconjugates and pseudooligosaccharides in water.

Recent trends in the synthesis of O-glycosides of 2-amino-2-deoxysugars

“…30,218,[227][228][229][230] Tetraacetate 101 can be easily prepared from either unprotected glucosamine 226 or from 2-amino tetraacetate 75a. 218 The latter approach is preferred if the synthesis of 101 in anomerically pure b-form is required (Scheme 19).…”

“…232 Cbzprotected glycosamines can also be obtained by consequent reprotection of azido or another carbamateprotected glucosamine. 160,227 The first reported glycosylations with 2-N-benzyloxycarbonyl amino sugars involved the activation of bromides. 233,234 Unfortunately, the Hg(CN) 2 -promoted reaction of glycosyl bromide 102 with glycosyl acceptors gave the oxazolidinone derivative 103 with migration of the benzyl group to the aglycone.…”

“…The efficacy of these glycosyl donors has been demonstrated in the synthesis of nucleosides243 inner core of lipopolysaccharides,244 heparin derivatives, 240,245-247 dibekacin,248 Lipid A derivatives,249 glycosidic lignan variants,250 neoglycoconjugates,227 solid-phase peptide synthesis,231 and antibacterial amino glycosides, 251 among others.Versatile applications of the allyloxycarbamoyl (Alloc) protective group 252,253 prompted Boullanger et al to investigate its participating properties in 1,2-trans glycosylation reactions 254. For this purpose, glucosyl…”

Synthesis and Application of Glycopeptide and Glycoprotein Mimetics

“…The obtained glycoclusters can be used to study multivalent interactions. Ichikawa et al explored the use of Steyermark's glucopyranosyl oxazolidinone for anchoring glucosyl moieties onto amines and thiols in aqueous media [67]. The method was applied for the synthesis of a urea-tethered glucosyl lysine conjugate and a corresponding cysteine conjugate.…”

“…Separation of the diastereoisomers was achieved by selective enzymatic hydrolysis of the N α -acetyl group of the L-amino acid by acylase I. After Fmoc protection, the building blocks were used in the solidphase synthesis of neoglycopeptide analogues of the mouse hemoglobinderived decapeptide Hb (67)(68)(69)(70)(71)(72)(73)(74)(75)(76) For the synthesis of C-glycosyl alanine derivatives, Wong and coworkers used an asymmetric Strecker reaction starting from C-glycosyl acetaldehyde derivatives [100]. The stereoselectivity of this reaction was strongly solvent-dependent and was reversed by changing from THF to CH 2 Cl 2 .…”