- A convenient synthesis of orthogonally protected 2-deoxystreptamine (2-DOS) as an aminocyclitol scaffold for the development of novel aminoglycoside antibiotic derivatives against bacterial resistance
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The development of new aminoglycoside analogues to reduce the emergence of bacterial resistance has become a topic of high interest. We describe here a rapid and facile access to orthogonally protected 2-deoxystreptamine (2-DOS), a meso-diaminocyclitol known to be a pivotal component of most active aminoglycosides. Our synthetic approach started from highly protected methyl α-d-glucopyranoside which in turn was converted by a Ferrier rearrangement into an enantiopure polyfunctionalized cyclohexane ring. Finally, two different N-protected groups were successively introduced. The first one was inserted as an oximino benzylether followed by a diastereofacial hydride reduction, working with Me4NBH(OAc)3 only in TFA at low temperature rather than in AcOH as usual. The second group was introduced by displacement of a hydroxyl group through a Mitsunobu reaction using a DPPA-DIAD-Ph3P system for azide transfer. The Royal Society of Chemistry.
- Bauder, Claude
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supporting information; experimental part
p. 2952 - 2960
(2009/02/02)
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- Synthesis of kojidextrins and their protein conjugates. Incidence of steric mismatch in oligosaccharide synthesis
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Kojidextrins are biologically important oligosaccharides that are involved in many physiological processes including protein glycosylation and bacterial growth. As part of our project to explore the role kojidextrins may play in bacterial pathogenesis, here we report synthetic routes to kojibiose (54), -triose (58), -tetraose (64), and -pentaose (69) equipped with α-linked (hydrazinocarbonyl)pentyl aglycon, using linear and convergent strategies. In the search for a rapid convergent strategy for the construction of extended kojidextrins, four kojibiose donors (1-4) were synthesized that contain acyl- and ether-type protecting groups in various ratios. These were tested to probe the influence of diverse protecting group assemblies on their glycosyl donor ability. Attempted condensation of these donors with kojitriose and -tetraose acceptors failed to give the desired products apparently because of steric mismatch between the donor and the acceptor moieties. A one-pot procedure was developed for the covalent attachment of the synthetic saccharides through their hydrazido group to human serum albumin (HSA) using Tietze's squarate method to give neoglycoproteins containing up to 28 saccharide units per HSA.
- Pozsgay, Vince,Dubois, Eric P.,Pannell, Lewis
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p. 2832 - 2846
(2007/10/03)
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