Chemistry of β-trimethylsilylethanol. II. A new method for protection of an anomeric center in pyranosides

Lipshutz, Bruce H.; Pegram, Joseph J.; Morey, Matthew C.

doi:10.1016/s0040-4039(01)82992-0

Cited by 86 publications

(19 citation statements)

References 9 publications

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“…We first planned to prepare the Forssman antigen pentasaccharide 2 a with a 2‐trimethysilylethyl group at the reducing end and derivatives 2 b – d , in which one and/or two galactosides are attached in place of the galactosamine units. The 2‐trimethysilylethyl group at the non‐reducing end is a lipophilic tag that allows for easy purification and can be chemoselectively removed by treatment with trifluoroacetic acid (TFA)11 or LiBF 4 12 for further derivatization. Our strategy for the synthesis of the pentasaccharide derivatives 2 a – d involved two one‐pot glycosylations combined with a polymer‐assisted deprotection (Scheme ).…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Biological Evaluation of the Forssman Antigen Pentasaccharide and Derivatives by a One‐Pot Glycosylation Procedure

Tanaka

Takeuchi

Jimbo

et al. 2013

Chemistry A European J

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The synthesis and biological evaluation of the Forssman antigen pentasaccharide and derivatives thereof by using a one-pot glycosylation and polymer-assisted deprotection is described. The Forssman antigen pentasaccharide, composed of GalNAcα(1,3)GalNAcβ(1,3)Galα(1,4)Galβ(1,4)Glc, was recently identified as a ligand of the lectin SLL-2 isolated from an octocoral Sinularia lochmodes. The chemo- and α-selective glycosylation of a thiogalactoside with a hemiacetal donor by using a mixture of Tf(2)O, TTBP and Ph(2)SO, followed by activation of the remaining thioglycoside, provided the trisaccharide at the reducing end in a one-pot procedure. The pentasaccharide was prepared by the α-selective glycosylation of the N-Troc-protected (Troc=2,2,2-trichloroethoxycarbonyl) thioglycoside with a 2-azide-1-hydroxyl glycosyl donor, followed by glycosidation of the resulting disaccharide at the C3 hydroxyl group of the trisaccharide acceptor in a one-pot process. We next applied the one-pot glycosylation method to the synthesis of pentasaccharides in which the galactosamine units were partially and fully replaced by galactose units. Among the three possible pentasaccharides, Galα(1,3)GalNAc and Galα(1,3)Gal derivatives were successfully prepared by the established method. An assay of the binding of the synthetic oligosaccharides to a fluorescent-labeled SLL-2 revealed that the NHAc substituents and the length of the oligosaccharide chain were both important for the binding of the oligosaccharide to SLL-2. The inhibition effect of the oligosaccharide relative to the morphological changes of Symbiodinium by SLL-2, was comparable to their binding affinity to SLL-2. In addition, we fortuitously found that the synthetic Forssman antigen pentasaccharide directly promotes a morphological change in Symbiodinium. These results strongly indicate that the Forssman antigen also functions as a chemical mediator of Symbiodinium.

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Section: Resultsmentioning

confidence: 99%

Synthesis and Biological Evaluation of the Forssman Antigen Pentasaccharide and Derivatives by a One‐Pot Glycosylation Procedure

Tanaka

Takeuchi

Jimbo

et al. 2013

Chemistry A European J

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“…Deprotection with LiBF 4 in wet CH 3 CN gave diol 18. 11 Compounds 19-24 were prepared similarly by addition of a lithium or Grignard organometallic to the methyl ketone.…”

Section: Chartmentioning

confidence: 99%

Synthesis and SAR of potent and selective androgen receptor antagonists: 5,6-Dichloro-benzimidazole derivatives

Guan

Alford

et al. 2007

Bioorganic & Medicinal Chemistry Letters

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“…The mechanism and an example are shown (Scheme 25). Noteworthy is the fact that, in the protection of anomeric hydroxy groups, 2-trimethylsilylethylation (Me3SiCH2CH2-) is sufficient instead of SEM because the glycosidic ring-O-C(l)-O(l) sequence in the former is a substitute for the ROCHP unit in the SEM group [73].…”

Section: 22-trichloroethylidene Acetalsmentioning

confidence: 99%

Reactions at Oxygen Atoms

Tsuchiya¹

2001

Glycoscience: Chemistry and Chemical Biology I–III

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Chemistry of β-trimethylsilylethanol. II. A new method for protection of an anomeric center in pyranosides

Cited by 86 publications

References 9 publications

Synthesis and Biological Evaluation of the Forssman Antigen Pentasaccharide and Derivatives by a One‐Pot Glycosylation Procedure

Synthesis and Biological Evaluation of the Forssman Antigen Pentasaccharide and Derivatives by a One‐Pot Glycosylation Procedure

Synthesis and SAR of potent and selective androgen receptor antagonists: 5,6-Dichloro-benzimidazole derivatives

Reactions at Oxygen Atoms

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