152964-71-1Relevant academic research and scientific papers
A Ring Contraction of 2,3-Di- O-Silylated Thiopyranosides to Give Thiofuranosides under Mildly Acidic Conditions
Abronina, Polina I.,Malysheva, Nelly N.,Litvinenko, Veronika V.,Zinin, Alexander I.,Kolotyrkina, Natalya G.,Kononov, Leonid O.
, p. 6051 - 6054 (2018)
A pyranose ring contraction of ethyl 1-thio-β-d-galactopyranosides has been discovered that proceeds with retention of aglycon under mildly acidic conditions (aq TFA in CH2Cl2). Key factors for success of this rearrangement are the presence of bulky silyl (TIPS or TBDPS) substituents at both O-2 and O-3 and a free hydroxy group at C-4 (derivatives with acid-labile protective groups at O-4 will also engage in this reaction). The rearrangement cleanly proceeds for 2,3-di-O-TIPS derivatives with two hydroxy groups at C-4 and C-6, acid-labile TES groups at O-4 and O-6, or one acyl substituent (Bz, ClAc) at O-6. A possibility to switch the direction of the debenzylidenation reaction in 4,6-O-benzylidene-2,3-di-O-TIPS/TBDPS derivatives by the choice of an acid (TFA, which cleanly gives furanose, versus AcOH, which cleaves benzylidene acetal only) may present an advantage in the divergent synthesis of selectively protected glycosyl donors (either in furanose or pyranose form) useful for the synthesis of biologically important oligosaccharides.
A versatile approach to the synthesis of mannosamine glycosides
Alex, Catherine,Demchenko, Alexei V.,Visansirikul, Satsawat
, p. 6682 - 6695 (2020/10/02)
O-Picoloyl protecting groups at remote positions can affect the stereoselectivity of glycosylation by means of the H-bond-mediated aglycone delivery (HAD) pathway. A new practical method for the stereoselective synthesis of β-glycosides of mannosamine is reported. The presence of the O-picoloyl group at the C-3 position of a mannosamine donor can provide high or complete stereocontrol. The method was also utilized for the synthesis of a biologically relevant trisaccharide related to the capsular polysaccharide of Streptococcus pneumoniae serotype 4. Also reported herein is a method to achieve complete α-manno stereoselectivity with mannosamine donors equipped with 3-O-benzoyl group. This journal is
Catalyst-free regioselective acetylation of primary hydroxy groups in partially protected and unprotected thioglycosides with acetic acid
Abronina, Polina I.,Kolotyrkina, Natalya G.,Kononov, Leonid O.,Malysheva, Nelly N.,Stepanova, Elena V.,Zinin, Alexander I.
, p. 36836 - 36842 (2020/10/27)
Highly regioselective acetylation of primary hydroxy groups in thioglycoside derivatives with gluco- and galacto-configurations was achieved by treatment with aqueous or anhydrous acetic acid (60-100% AcOH) at elevated temperatures (80-118 °C), avoiding c
Synthesis and solution-phase conformation of the RG-I fragment of the plant polysaccharide pectin reveals a modification-modulated assembly mechanism
Scanlan, Eoin M.,MacKeen, Mukram M.,Wormald, Mark R.,Davis, Benjamin G.
supporting information; experimental part, p. 7238 - 7239 (2010/08/13)
The syntheses of pure RG-I fragments of key plant matrix biomolecule pectin using a counterintuitive late-stage convergent cis-glycosylation has allowed detailed analyses of their solution-phase conformations, metal binding affinities, pKa values, self-assembly equilibria, and diffusional kinetics. These reveal a striking, right-handed 31-helix that provides an effective and repeating lateral display of putative liganding carboxylates. Moreover, these heteropolymeric structures allow units as short as tetrasaccharides to self-assemble through carbohydrate-carbohydrate interactions that are induced by the presence of Ca(II), a known dynamic trigger in planta. These self-assembly properties can be switched simply by the addition or removal of a single methyl group in this repeating unit through methyl (de)esterification, another known dynamic trigger in planta. Together, the combined effect of Ca(II) and methylation revealed here suggests a concerted molecular basis for these two major dynamic modifications in planta.
H2SO4-silica-promoted 'on-column' removal of benzylidene, isopropylidene, trityl and tert-butyldimethylsilyl groups
Roy, Bimalendu,Verma, Priya,Mukhopadhyay, Balaram
experimental part, p. 145 - 148 (2011/02/27)
H2SO4-silica-promoted removal of benzylidene, isopropylidene, trityl and tert-butyldimethylsilyl groups from sugar derivatives was accomplished by following an 'on-column' protocol in a virtually waste-free condition.
Dicarboxymethylated glycolipid derivatives as cell adhesion inhibitors
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, (2008/06/13)
There is provided a novel series of O-carboxymethylated α- and β-glycolipid compounds of the formula STR1 wherein R is an acyl residue of a fatty acid; R1 is --(CH=CH)m --(CH2)n --CH3 ; R2,
PARTIAL SUBSTITUTION OF THIOGLYCOSIDES BY PHASE TRANSFER CATALYZED BENZOYLATION AND BENZYLATION
Garegg, Per J.,Kvarnstroem, Ingemar,Niklasson, Annika,Niklasson, Gunilla,Svensson, Stefan C. T.
, p. 933 - 954 (2007/10/02)
Partial substitution by phase transfer catalysis giving monobenzoylated and monobenzylated products from 2,3- and from 4,6-diols in ethyl 1-thio-D-hexopyranosides with the β-gluco, β-galacto- and α-manno-configurations are described.Two disaccharide thiog
